Replacing Glued on IBC valve

Any ideas about how to replace this IBC tote valve? The valve stem cracked, and it leaks constantly. Has only been used for water, trying to give it new life as a rainwater collection system.

The whole valve mechanism / spigot looks like it is glued on, rather than screwed in.

I bought a replacement valve (with screw in threads) off eBay.

Any way to make that work? Or should I try a different solution? I can't get the whole valve off, although I only tried turning it relatively gently with a pipe wrench.

If the orientation in the photos throws you off, the tote is currently upside down for maintenance.

I think IBC totes are made from HDPE, so glue is not going to stick. You will want to have a mechanical connection (threaded). I would try to cut the leaky valve away leaving as much plastic at the valve base where the tank connection is, as possible. Then I would tap the hole into the tank to take a suitable pipe nipple. You can make a reasonably effective pipe thread cutter by purchasing a galvanized pipe nipple of the desired size and cutting four slots perpendicular to the threads with a side-grinder and wafer disc. Then bend the four resulting tabs inward toward the centerline of the pipe nipple a little bit by hammering with a rubber mallet or block of wood. The cut edge from the grinder disc cut is sharp and will cut thread into the plastic; advance your homemade tap a little at a time and back out to make clean thread cuts. Once the tap will go all the way in, remove it and put in a proper nipple with some teflon tape on the threads, and your valve.

I would use a rubber coupling like this one: