yes remove the top cover , put it in 1st gear to ease this operation , same on refiting
to fit new springs you need to remove the welch plugs there are small holes in the top cover to stick a thin punch in and pop them off,
the square headed dowel bolts has to be undone these can be more than 'tight' done up by a gorilla.
if you undo these the shaft can be used to pop the plugs out , thye can be reused with smear of sealer
take care between each shaft is a series of balls and pins that act as interlock to prevent two gears at once .
good time to re bush the remote , but dont attempt to change the 0 rings in the kit these seal the front short rod in the top hsg, nearly impossible as you will chop the new ring with the old shaft and its another of those square dowels to shift leave that bit alone .