Chevron Models' 1/12 scale M'76 transkit instructions in English

Joaquin (f1m name: Joaquin) and I have completed an English instructions set for Chevron Models' "M'76 transkit", to make a 1/12 Tamiya 1975 Yardley M23 into a (James Hunt-like) 1976 McLaren M23.  These instructions are complete, and meant to replace the somewhat misspelt, hand-written, English margin notes that came with some M'76 transkits.  They also:

removing perished tyres

can anyone offer advice as to removing old perished tyres. I have a 1/12 Lotus 49b whose tyres have perished and they look as though they are punctured. I have managed to source some new Firestone tyres. would appreciate any advice as to how I should remove the old perished tyres without breaking tbe wheel from the hub.