Repeat offender modder here.
I love letting my imagination go wild.
First, I would get some decent, but not overly expensive tools. Then I would get a working but cheap watch to practice on. No harm, no foul if you bugger it up.
At the same time I'd check Dagaz, Yobokies, Motor City, and as many other sources to check parts availability. There are tons of threads on WatchUSeek in the Seiko forum. They also have tutorials, as well as Youtube.
I can't help with specific references as I use SKX and SRP models to mod. Never got into the smaller sizes.
Experiment, have fun, and keep us updated.
dP
Here are a few of mine:
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