That's a big foot (roo). You're going to get to bond with your nemesis: I'd start out with a twenty minute soak in warm water and Epsom salt (drawing agent). Mix in, thoroughly (it'll want to sink to the bottom of the pan), sufficient betadine to tint the water well. Place the roo on your lap so that affected foot is on top (roo should be shifted so leg is extended. Place a chair/stool/whatever with the pan (plastic flat bottomed storage container on a towel is very good) next to your chair (adjust height with book/mags). Place the roo's foot in the solution and sit there (sing to him talk to him whatever). If it is quiet enough he'll probably nod off.
Examine the cleaned foot closely: Any possible punctures/cuts/etc.?
He really needs to be kept somewhere where he can't move around (as much) and where you can keep the foot relatively clean (if there are any open wounds).
If that foot is as swollen as it appears in photo (would like to see comparison with good foot), he really needs a trip to the vet (bumble foot - if that's what it is - in a heavy, feather footed roo is labor/med intensive treatment course).
We are just now seeing the `talons at the end of tunnel' with our guy - month and a half of meds/soaks/dressing changes (thorn through the top of the foot). No excess ped plumage, however. Our vet has our guy on 250mg Cephalexin BID.
Best of luck!