Product review (5 stars): Change just the large coil first, then test. Fairly easy repair.
Kit consists of 3 coils. Try replacing just the largest (single) coil first, as this appears to be the one that turns the gas valve ON (coil closest to the burner). That worked for me. The matching pair of coils on the OFF (closest to the gas supply line) valve need to be stronger to make sure the valve turns off (thus, two coils).
The color coding on my old Maytag dryer wiring did not match the colors or polarity on these coils, but that's not a big deal as they are AC coils. This might be an issue if you must replace the two smaller (gas OFF) coils, since they should work as a pair. Just go with matching up all the White wires, and wire one coil at a time if that's the case for you (very unlikely).
My dryer has a pop-open inspection door to view the burner. You should see the ignitor get red-hot, hear the valve plunger click as the coil pulls open the gas valve, then see the gas burner ignite. If the ignitor glows but there's no flame (no gas), the ignitor will automatically turn off, then try the cycle again a minute later. Leaving your clothes to tumble for hours with no heat will wear them threadbare.
Kit comes with clear diagram/instruction sheets, 2 wire nuts for each coil, pre-stripped leads, and a new O-ring for sealing each valve, so has everything you need for this fix. Remove nuts from coil cage to expose coil and remove old rubber O-ring. Cut the old coil wires close to the coil, strip the wires, connect the new coil wires tightly with wire nuts. Then assemble the coil, flat plate, and O-ring as a unit. Slide everything gently over the plunger (round post) and secure. My model has a small clamp holding all the loose wires in place.
You'll need small nut drivers, wire cutter, wire stripper, and you'll have to remove the front of the dryer (mine has two phillips screws near the bottom of the front panel). Turn off the gas (mine has an internal shut-off near the gas valve) and pull the AC plug from the wall.
Clean out all the lint with a vacuum and the (flat) cushion attachment while you're in there, especially inside the exhaust/lint filter channel (mine had a glob of lint stuck in it the size of my fist, though it still passed air). A bunch of screws held a cover for that channel, right in front of the lint filter. Don't touch the ignitor -- they're fragile.