The two main ways to attach focusers to tubes are
1. Three screws spaced at 120 degrees or
2. Threads on the tube.
So give it a good look and see how you can get it off. I'll give a warning that is liked not relevant. Some scope makers, specifically Takahashi, like to make sure the focuser in back and lens cell in front do not unscrew by putting in tiny grub screws which go through the threaded part of the focuser (or lens cell) and tighten directly again st the threads on the tube. If you don't see three obvious screws where focuser or extender is inserted into tube focuser=male, tube = female) but instead see the tube as male inserted into the focuser, then you probably have a threaded tube and need to check for grub screws or any other locking screw that prevents rotation.
That done removal is fairly straightforward. Focusers are fairly simple. Inspection should reveal how to remove extender.
If you retest focus under daylight conditions pick something far away.
So far as I know only Tak does the grub screw nonsense and maybe they've wised up and stopped. I swear to God anything to do with a focuser Tak is going to make unnecessarily difficult. Stellarvue has a history of intelligent machining you'll likely be fine.
Edited by gnowellsct, 24 May 2018 - 04:23 PM.