The seats are easy to swap just remember to do one set of bolts, then slide seat forwards, disconnect battery, leave for 5 mins, then do next set of bolts, disconnecting all the harnesses whilst your at it, obv park somewhere with enough space to open the door fully.
Steering wheel is quite straight forward but mine was a pain in the ass, it has those safety screws star shaped in it with loctite around the edge and the notch in the middle to stop you using a standard tool, i broke 1 or 2 trying to remove mine, came off in the end tho, make sure you leave the battery off for this....
Also having watched a m8 explode my passenger airbag (safely of course ) try not to take one of those to the face!