Hey everyone, I'm working on the valves on my '79 GS750. Most are in spec but there are a couple in dire need of fixing. The manual shows that I need to use a "tappet depressor" to be able to pull the shims out but I can't find one of those in town and I don't wanna wait for one in the mail. Has anyone done this before with a screwdriver or something? Is it even something I can do without the depressor or is that tool an absolute necessity? Any advice helps, thanks!