kit p/ns are ssb602 & ssb603 from memory,,, one is for the std mini & the other is for the "S" valve,,, forgotten which way round it is
& drill a hole into the back of it,,, thread the hole,,, have bolt of same thread handy & weld a lever to it,,, trim the pring down a coil or 2,,, fit a flat washer of correct size to fit into the cyl before re-fitting newly kitted valve spring & piston assy,,, add lock nut with (lever welded to it) onto the bolt before fitting & you can add an o-ring to help seal it if you so desire
i think we used to use a one cent piece as the flat washer years ago
