Found a guide on how to do it without welding but not sure if it works too good,
http://skyline.uptomyneckinit.co.uk/skyline/index.html
The welding method does work, and if you are going to do it, be careful. Just weld the centre of the stud, dont fill it completely, and gradually build up the weld. you might have to try it a few times, as the weld might break. And I hope they are all not at the back of the engine next to the bulkhead, as space is tight :-( Best of luck

