Didnt realise they were still stuck, get a hot air gun and heat up both sections untill you cannot touch them then cool down the bottom section, do it at least 4 times with water or let it cool naturally. Last time just leave it cool. Then go to bed. In the morning try undoing them.

repeat until they seperate, they just go easily all of a sudden. (its ok they are baked in an oven when they are made and are fire proof.)
It does work I have done it quite a few times now. The tape trick is mine and it also works. Using a lubricant doesnt do much except push the joints further together, you really want a bit of wear and the buffer tape to stop compaction, so they are easir to work with on a daily basis.
Hope this helps as they say
