its simple to remove the splash guard.
you have to do it one at a time.. start by removing the driver side wheel.. the black splash guard is held in by 4-5 plastic screws. 3 in the wheel well.. 2 under the car where the splash guard ends are.
once thats gone.. put the wheel back on and you can start to roll your fenders using a (wooden) baseball bat (i wrapped mine in a towel so i dont crack the paint)
heres some instructions that i used to do it..
http://beta.vtec.net/articles/view-a...rticle_id=3511
as for the tires they are Nitto 215/35 ZR/18