I have the same ones for my next project Chally...
I put some partial stripe on the side of 'ol Grrreen earlier this year... It's really not too hard... but a little freaky...
The biggest thing is to make sure that the surface is absolutely clean, clean, clean! Or the sticker will tend to bubble and peel...
My car never sees wax, so I never had to remove any. But I've read that it is a good idea to take it off if you can.
Basically, use some mild soapy water... rub it all over the area you are going to work on with a sponge... (get it pretty wet if you are concerned about it sticking too quickly...) The soap will tend to stop the stripe from sticking so that you can move it around to where you want it.
When I did it, the stripe really didn't stick much at all until I pressed it down with the plastic squeegee... Once you do that, you are comitted. It will not move anymore and if you peel it, you will wreck it.
Good luck!!