Drill Press and a tap and a little time on the shop bench. Fairly simple transition. If you can find a TC 209 screw in adapter, then all you are required to do is drill the hole and tap it for threads. The one that I purchased was $12 or so. Now, the one made from a large headed bolt was really more than I expected in labor. The hardest part on this one was drilling the small hole all the way through the bolt, then drilling the screw in breech plug and tapping it all the way through to receive the bolt. Then the head of the bolt is drilled out to accept the 209 primer. This one would not be repeated from the labor and pain in the AXX it was. I am pleased with both of them and the 209 conversion is the best upgrade for this rifle. The best is to find a screw in 209 adapter and work from there.
I got rid of the 50 cal encore, one 50 cal hawkin, one double barrel Trail arms, and fixin to let another 50 cal hawkin and 50 cal TC Scout go. These 58's are excellent to use in the field. If you ever think of letting it go, I would be interested cause I just like the thangs. Heeeee!!