[tdq]

I wouldn't bother removing any of the keys, at first. Get a nut extender, string it up, give it a go, see how it works. Get a nut extender, bung it on and see how it goes. There are many fine musicians who play lap slide like this, Kelly Joe Phelps, John Butler for example, (and usually on a 6-string acoustic) - the nut extender will probably be a bit narrower than the 12 string nut but it'll still work. If it works and sounds good then after a bit you can replace nuts, tuners. I just use regular strings (12 or 13s) but many like them heavier for slide.

Nut extenders are cheap as chips
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