To replace the seal remove the prop bolts and move the prop out of the way. There's a large nut in the centre of the flange (30mm I think) remove that and it's washer and the flange will just pull off. The seal can then be levered out with a screwdiver or similar item and a new one carefully knocked in (make a note of how far the old seal was recessed in the housing) Inspect the flange land (the part of the flange that the lip of seal runs on) If it's got a line in it from wear, then it'll have to be replaced. If it's ok then grease the land and the inner lip of the seal and put it all back together. Bear in mind that the flange will have some play in it - this is normal as long as it's not excessive - more than 8mm total movement.
The belt - you can do it with the cowling on, but it's fiddly. The PAS belt is in front of the alt belt, so you need to remove that first (from underneath is easier if you leave the cowling on).
Les.
