This is from memory, but I just did it a week ago.
You have to remove the pump.
Set the crank to 15 degrees after TDC. Turn clockwise by hand.
Remove the viewing port plug on the IP
Use a mirror and light to check for the timing ridge. If it is in the center of the window, then the timing is correct. If not, proceed.
Remove the intake manifold
Release the fan belt tension.
Remove the upper radiator hose
Remove the power steering pump pulley
Remove the vacuum pump
Disconnect the fuel lines to the IP
Disconnect the hard lines that go to the injectors. It will be easier if you remove them all together.
Disconnect the fuel return line from the engine side of the IP
Unplug the fuel control valve electrical connection
Unplug the IP harness on the PS of the engine compartment
Remove the center bolt in the timing gear. IT IS LEFT HAND THREADED.
Remove the chain tensioner. PS of the block, inline with the timing chain path.
Remove the rear IP mounting bracket to the block
Remove the 3 mounting bolts
Remove the IP to the rear and up and out. Try not the touch the battery cable connection on the starter when doing this. It would not be a bad idea to block that connect off with something non-conductive.
Retrieve the timing adjustment assembly. It will still be attached to the block.
Turn the pump until the timing ridge is in the center of the viewing port.
Lock the pump timing in place.
You can purchase a tool for this job or make your own :
http://www.peachparts.com/shopforum/diesel-discussion/354302-diy-ip-timing-lock.html
Reinstall the pump as far as:
make sure the IP timing adjustment assembly is in place and the head is in the notch properly
the pump shaft splines are fully engaged in the timing gear and the center bolt is in place
the 3 mounting bolts are installed and holding the pump in place, but not tightened yet
the chain tensioner is reinstalled
At this point I rotate the crank 2 twice by hand and check the timing of the IP. If it is OK, then I finish the install.
Do not forget to finish tightening the center bolt on the timing gear.