The do-it-yourselfer can saw out a couple of wooden discs, put them in place and screw them together (commercial plastic discs are widely available).
Iyenzo -- ngokwakhe -- ingasaiha amacwecwe amaplanga ambalwa, uwabeke endoweni uwadibanise kunye (amacwecwe eplastiki axhaphakile kwindawo yonke).