youve got two options really.
1-cheat,dont remove the tyres. sand the whole rim down as close to the tyre as you can,get some alloy compound and add if needed atall,then sand it to the shape of the ally, then spray and laquer
2- do it properly.get the tyre removed. then sand and add any compound and spray an laquer.and thats about it really.unless they have any buckles atall,in which case youd heat the rim where its bent and tap it straight using a copper mallet with a block of wood in between the hammer and rim