How do i fit TC4 Foam bumper to my mardave?

[Tempest501]

This prob is a really dumb question but I cant figure it out. I have taken the tc4 bumper and it will slide onto the front body posts of my mardave but it touchs the wheels and they would not be able to move. I bought the Mardave 2n hand and im not really very knowledgable about building things as yet.

I check the long metal chassis to see if there were any hole to move the wheels backwards but I dont think there is.

Any suggestions? I am hoping to race it later today so would really like to figure out how to get this bumper on. I didn't want to start cutting away at it before asking as the bumper is from my T/C.

Many thanks