What Type of Slide Hammer were you using?
The older Euro made Prechamber Pullers need a Slide Hammer with 12mmx1.75 threads.
I think the USA Made Versions sold by Baum Tool, ZEDMAK Tool and El Paso Tool you will need a slide Hammer with 5/8" something threads.
Aoutozone used to have a Free reantal on the 5/8" threaded Slide Hammers and they have the 5 pound Slide/Weight needed. Those Slide Hammers sold with the tiny palm sized Slide/Weight are going to be harder to use.
There used to be a Prechamber Puller in the Tool Rental Program.
Tool Rental List
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The Slide Hammer pictured is mine but the one Autozone rents is similer in size. Besides the larger Slide/Weight the Rod it is easily 2+ feet long.
There is a made in China version of the same Slide Hammer that has the 12mm Threads (for info you can see what is selling on ebay.).
The one in the Picture is also made in China but I bought it back in the 1970s and it has the 5/8" I think it is 16 or 18 threads on it.
when you slide hammer off the Pre-chambers in on the Engine it is a good idea to have the Hood straight up in the Air so that when the Pre-chamber pops out they whole puller setup does not pop up and put a dent in the Hood.