if it has a drum then it is fairly easy you just need a lock and a touchhole liner.if it has a snail type breech like most Hawken rifles then a new breech plug and a whole slew of work is neccesary and so ,MAYBE not really worth it,but that part is up to you,it could still be done.After it is done ,if it's done right you can switch them back and forth and this can be useful and /or neccesary if you want to use the same rifle in some primitive seasons and still want a percussion at other times.