Is it a water-slide or some kind of an adhesive-back sticker?

I have seen some videos where vinyl stickers are applied using soapy water and a plastic smoothing tool. The water lets you get precise positioning and when it dries the adhesive can grab. The water would probably damage a paper sticker though.

In the past, I trim the backing paper if it's larger than the sticker. Then I use blue painter's tape to precisely position it. I use the tape only on one edge, like a hinge. That allows me to get under on the other side and start peeling back the paper. I only peel back a little bit by the tape edge to get it started. Then slowly pull the paper out sticking it down as I go.

I recommend watching YouTube videos of these techniques.

Its a grip decal for the spinning disc not waterslide.

For mine I removed the disc and removed the old sticker and residue. Then applied the new one and re leveled the height of the disc.