The answers can be found on the site but figure I localize it to the T&T: brakes.
I'm running dual discs on my 72 750 but this procedure is also relevant if you just want to use a banjo instead of hard lines. Its all straight forward with the exception of removing the flare seat inside the caliper where the OEM hard line installs into.
What I did (also suggested in other posts) was drill the flare seat hole just large enough to screw in an ordinary wood screw. Some use pliers and a hammer but if you want, just leave the piston in the bore (it will mar the piston so I only suggest doing this if you're installing new pistons). Another suggestion is I happen to have a 27mm socket which dropped right in the bore. Proceed to screw and eventually the screw will stop against the piston/socket. Out it comes. I suggest chasing the bleeder holes with a tap (M10x1.25).
