Find the correct torx bit and remove the remote from your bars.
undo the seat clamp and remove the bolt/lever etc
Gradually feed the hose from the remote end towards the hole in the frame it comes out of while slowly pulling up on the post – work a little bit at a time and if you have any mid point exits around the BB for example you may need to work the cable around those too.
Eventually your remote should be right up against your frame exit/entrance and you should have the post fully out with just the hose going down into the seat tube.
I you are lucky you can get the hose through the gap in the seat clamp, maybe tease it open with a plastic tyre lever a touch.
Refitting is the reverse. Don’t forget to clean the post and apply some nice fresh grip paste.
If you dont have enough hose (which is unlikely unless you have 580mm wide bars!) or the hose won’t fit through the clamp then your best bet is to unscrew the hose from from the base of the post or worst case from the remote and re-thread it (tie some string or something to it if you do this using the red barb tool (couple of £ on ebay).
If you have a connectamajig on the bottom of the post you might get away without a bleed but if not then you will need to bleed it. Plenty of videos about doing that, I am sure sram also have a video on how to remove your post too.
The evidence suggests otherwise.
Have a cup of tea and a further think about it.
^ This 😉 😀