Originally Posted by AdrianM
You can use a sharp 1/8" drill bit or order a 1/8" (.125) reamer from a tool supply company online like McMaster Carr.
But do yourself a favor, spend the money, and get a .125 reamer. It's the right tool for the job. I think I bought one for $12 from Niftech, they're probably $8-10 from McMaster-Carr. You're really only removing just a hint of material--I can run my reamer in with my fingertips--but it makes a BIG difference. Remember to do as Adrian instructs, though, and ream the steering blocks AFTER you install the axles.
Scottrik