I'd remove the engine for better access, theres not a lot you need to disconnect to whip one out, leave the box attached, or split it when theyre out and have a look at the clutch. Its not that hard a job but its best to do the timing belt aswell, then you may aswell do the waterpump, aux belts etc. it all adds up haha. I'd do both crank seals tbh, saves ruining a clutch when the other one fails, not to mention doing the work again lol.