as Kelv says there easy as anything to change over, i swapped one this morning in about 20 minutes no trouble, 4 bolts and there out.
just make sure there definately comfortable, i have got a pair of bucket seats and there great on a winding road etc, but in terms of practicality there not great, for the moment it makes more sense for me to have standard seats with driving around alot and getting in and out, reversing is awkward aswell if there too supportive, suprisingly awkward to twist your body. im still keeping them though, when it comes to a spirited drive on a country road there amazing, if you around town alot or doing long motorway distances then i would make sure they are definately comfortable for a long time first (they will all be comfortable when you first sit in them, its whats there like an hour or two later thats different), make sure the angle is comfortable aswell if there not reclining.