To remove the roll bar on a SL R129 Jack and support the nearside chassis then remove the road wheel, belly pan (engine under shield) and the nearside wheel arch shield panel that the roll bar passes through. Wire brush and use a good penetrating spray on all the fixing bolt threads: 2x on both hangers and 2x on each lower wishbone position.
Place a support packing under the raised wishbone and lower the car gently onto it to release any torsional tension between the two lower arms. Remove the roll bar hanger bush pins and saddles (13mm nuts and pins) and then remove the two nuts on the near side lower wishbone mount and slacked the ones on the off side. Release the roll bar, and then pull it out from the offside bush.
Once the roll bar is removed the offside bush can be unbolted and removed. You may find that the roll bar is corroded badly under the bush contact areas, this obviously must be removed and cleaned. A good coat of protective paint will provide future protection.
Once the paint is dry, slide the new hanger rubber bushes over the ends of the roll bar, use a little washing up liquid to ease the bushes round the bends of the bar. Offer up the roll bar and position the hanger bushes centrally and in the correct position to give balanced lengths at each wishbone/bar tip. Push fit the nearside wishbone bush onto the roll bar. Loosely fit the offside bush to the lower wishbone and slide the roll bar into it (use some washing up liquid if needed)
Offer up the bar whilst getting a lower nut and pin started in each of the hanger brackets and saddles, this will support the bar fully while you position and fit the nearside lower wishbone roll bush and saddle. Once you are happy with the fit tighten the hanger pins fully then the two wishbone bush sets. Refit all the parts removed to gain access to the roll bar, refit wheel and road test.