you will need to borrow, buy or fabricate your own timing belt tools to do the process below.
there are shortcuts and ways to improvise the tools, but its best if you can get ahold of the correct ones.
once you have the proper lockdown tools for the timing belt system. Cam lock, pump pin, tensioner pin wrench, cam pulley puller, and counterhold tool, you can do the following...
Remove the 90* elbow going into the intake,
remove the upper timing belt cover
remove the valve cover
remove the vacuum pump,
Then you need to set the car to TDC thru the inspection window on the flywheel end.
lock down the cam, lock down the pump, make sure the flywheel is on TDC thru the inspection window, loosen the tensioner and pop the cam pulley loose from the cam with the puller ir the use of a punch thru the plastic backing plate on the outside rim of the pulley... DO NOT HIT THE CAMSHAFT with a stray hammer blow if you go this route
with the engine rotated to TDC in the inspection window, the cam pulley loose and the camshaft locked on the vac pump end, you can lock the injection pump with the pin, loosen the 3 pump pulley bolts and skip the pump pulley one tooth on the pump in the direction that will get you some adjustment in the advanced direction ( so turn the pulley opposite of the way you were turning the nut on the pump with the wrench)
once you get the pump pulley skipped one tooth, you can then reset the tensioner in the clockwise direction with a little mirror to make sure its lined up properly.
with the tensioner reset properly, you can then tighten the cam pully to 40 ft-lb while counterholding the cam pulley so it doesnt turn the engine. you want to be double checking the crank is on TDC thru the flywheel inspection hole after each step. you do not want it to move. if it does, loosen both the cam bolt, pop it loose from the taper, loosen the pump pulley bolts and readjust the crank to TDC. (in other words, dont let it move~! its a PITA to fix it)
with the crank set to TDC, the Cam pulley tightened to 40 ft-lb and the 3 pump bolts tightened on a locked injection pump, you are all set to pull the locks, put the vac pump back on make sure the tensioner is still set properly, double check the tightness of the tensioner nut, and that the arm is in the hole it fits in and put the valve cover and reconnect the intake piping.
THEN you can restart the car and see where the timing is.
make adjustments as needed.
best of luck. hope you are handy and comfortable with your tools.