[Droid Incredible Q&A, Help & Troubleshooting] demarcmj:
I just replaced mine this weekend. I attached some before, during, and after pictures...

These were the guides that I followed:

Part 1: http://www.youtube.com/watch?v=TfpPS7oO4Q8

Part 2: http://www.youtube.com/watch?v=GJMAmKpk20c

Personally, I went with just the glass/digitizer (your first link) and it went fine. The glass is difficult to get out of the housing, but it's not that bad. It probably took me 20 minutes to get the old glass out, maybe 5 minutes of cleaning goo from the old adhesive, and probably another 5 minutes to put the new glass back on.

Some Tips:

The pry tool that comes with it is very cheap. I would suggest using it sparingly until you get to the LCD panel extraction and glass removal. You want it to be as in good of condition as can be when you get to those later steps.

Use a blow-drier to heat up the adhesive, and get it to the point where you almost cant touch it. I used some yellow kitchen gloves so I could get it a little hotter and still be able to hold it. I used a combination of my hands and the pry tool and worked mostly along the sides and top first, then separated the bottom last.

The guy in the youtube videos uses glue, but you shouldn't need that. It comes with pre-cut adhesive strips, which work great. One word of caution though... The sheet that they come on is scored for you, but I suggest using an x-acto to cut them out. This is especially important for the thin rectangle that goes around the outside of the glass. You really don't want to pull on that... you don't want it to get stretched or twisted. Summary: the strips work great, just be careful extracting them from the sheet they come on, and placing them on the phone.

Don't forget to get the red earpiece grill off of the old glass before throwing it away. You'll need to super glue that back onto the housing, but it's really easy to see where it goes. This should be the only thing you need glue for.

When removing the glass, cleaning up gunk from the old adhesive, and applying new adhesive, be careful of the electronics at the bottom for your capacitive buttons... you definitely don't want to harm or obstruct those.

This should probably go without saying, but make sure not to touch the inside of the new glass, or the LCD panel. You don't want fingerprints or dust inside the phone. Even if you don't touch it, I would still give it a shot of compressed air right before putting it in, just to make sure there's no dust.

I would say that it's probably worth the extra $10-12 bucks to get it with the housing already included, but it's definitely not necessary if you want to save a little money. As I said above, it only took me about a half hour to get the old glass out and the new glass in, and from what it sounds like, there is still some effort involved even if you get it with the housing (moving the circuitry from the old one). I wouldn't worry about breaking the frame... it's pretty strong. If you break it, you're doing it wrong. Although, if your frame has some scrapes and other assorted road rash on it like mine does (see first picture), then maybe you might want a new one anyway. Another consideration... the reviews on Amazon for the one without the housing are much better, but that could just be because of people who don't know what they're doing... who knows.

If you have any questions, I'd certainly be willing to help... PM me if you want. And if I'm going to be around when you go to actually do the replacement, I can give you my gchat address in case you have any questions during the process.