Introduction: Guitar Hero II Guitar Cake Tutorial. Decide to make a full size replica of the Guitar Hero II guitar in cake form. Spend the next few weeks freaking out and searching for instructions on fondant icing and cake decorating!
Pick up bits and pieces for making the cake over the course of the month... spending over $100 just on "stuff". For me this meant buying icing, a rolling pin, a rolling mat, palette knives, an icing smoother, cake board. Luckily I already had bowls, a mixer and a few bottles of wine in the cupboard. Step 1: Get Started With the Fiddly Bits. Cut out templates for the cake (I used the actual guitar to make my template) and start making the "extra" pieces by rolling out coloured icing and cutting to size. Put these in an airtight container to harden. Step 2: The Cake!. Because the guitar is so long and my oven was so small I ordered a sheet cake from a bakery. Its likely that the first person you speak to won't know what you're talking about so ask to speak to the baker and get a full sheet of 1" butter cake, un-iced and leveled. Or you could make a bunch of cakes and join them together. Sheet cake is easier!
Look at the sheet cake and wonder how you will cut all the pieces out, use wax paper to make templates (make sure you have right side up and wrong side up layers so you have a flat surface on the bottom of your bottom layer and top of your top layer) and then cut with a sharp knife! Put all the cut off pieces of cake in a bowl to snack on. Step 3: Laying the Cake to Rest.. You will need to cut a piece of cake board to fit into box that the actual guitar came in (this is super handy for transporting the finished cake!) then you can put cake in box and go to bed. It will rest and settle and you can get some much needed sleep in readiness for the icing excitement to come! Step 4: I Hope You Have Mixing Bowls!. When you wake up, freak out a little about how this is all going to come together since you're going to a gig and have a house guest for the weekend.
Before the gig, start making icing (white chocolate butter cream), filling (dark chocolate ganache) and drinking wine (brown brothers, dolchetto and syrah). The wine will relax you some what and make the nerves go away for an hour or so.
Put the filling in the fridge/freezer to cool and thicken while you set up the next part. Step 5: Its Icing Time!. Put a thin layer of icing on the cake board (under where the cake will sit) and lay the first layer on the board with the right side up. you do not want the cake sliding off when you move it around! Put the icing in the fridge now to cool while you do the filling.
Once the filling has cooled in the freezer to make it solid enough to spread without running down the edges cover the first layer liberally. dont go to close to the edges (it will discolour the outer icing if it bleeds out). 
Stand back and marvel at the first layer being complete. then put the top layer of cake on (so that the flat bottom of the cake is your flat top surface). Wow! it looks like a guitar. 
Brush away all the crumbs from the cake and using the icing which has now been cooled in the fridge cover entire cake in a thin layer. This is to seal in the crumbs as well as adding some moisture. Step 6: Rolling Out the Fondant. Now its time to get rolling! Kneed the fondant icing till it is softened and then roll out, using the wax paper template to check the size. dont forget you need overhang to cover the sides. If you have any icing remaining make sure you wrap it in clear film or it will harden and be unusable.
FREAK OUT about how to get the massive flat icing onto the cake, request assistance from someone if you can or roll the sheet over a rolling pin and then roll back over the cake. GENTLY! You do not want the fondant to tear.
Lay the icing flat on the cake and gently pull the rolling sheet back without stretching the icing. Smooth the corners and press the icing to the cake firmly but not roughly. Use a fondant smoother to remove finger marks and any weird lines. Cut the excess icing from the board and press the icing under the cake, smoothing as you go. 
Stand back and marvel some more at the icing being half way complete!  Step 7: Time for the Black Fondant. Kneed the black icing with 1/3 white icing to get a better consistency to work with (it doesnt ruin the colour at all! thats how much colour is in the icing!) and cover the parts of the cake iced with white fondant with clear/cling film to ensure you don't stain it with the black icing.
Roll out the black icing, lay on cake and shape as for the white icing. 
Stand back and rock out to the awesomeness that is the cake.
At this point I put the cake away in its box and went to go see YOU AM I! ROCK ON! Step 8: Almost Done!. Now that the cake is done you can get to finishing the fiddly bits!
Bend a cable knitting needle to make wahwah wand and put black icing on end to harden. Cut out details from the hardened flats of icing you make earlier. Put together on cake with royal icing. 
Drizzle royal icing on the back of edging ribbon and press to the bottom edge of cake. hide joins in the join of icing. 
Stand back and marvel in amazement at the finished cake!  Step 9: Have Your Cake and Eat It Too!. Go to party, put candles in the cake, sing badly then cut up cake and eat!
ENJOY!
ps. The body of this cake fed about 40 adults and the black iced neck of the guitar was not eaten until the next day. The black icing will make your teeth go purple until you brush them!