if you are sure you have the correct non worn out key the easy solution needs a replacement column, run a sawzall (or hacksaw if you have nothing better to do) and cut straight down through the top of the column, that's where the lock that's trapping the wheel on is, about 3/4-1" down should do it and you can get the wheel off and strip the useful stuff of the column. sometimes you can gut the key lock out and not kill the column but it can be a bitch