I accidentally dismantled mine. It was a bit tricky to get back in, but I managed it without too much hassle.
First off, make sure you’ve removed the spring. No point fighting against it. You can reinsert it later from the bottom. Next make sure that the latch mechanism is released by fully tensioning the cable with the barrel adjuster at the lever.
Get a bit of grease to help stick the rods to the inner post, stick the rods in place and then attempt to insert (make sure you have that brass ring in place beforehand, too). When inserting be gentle and slow, much like you would with a lady. Giving it a bit of slow gentle a wiggle can help. Just keep persisting, in and out, until you can get it all the way in.
I found the front rod gets caught on something, a lip or whatever, whilst inserting so small movements can work it past the obstruction. Just keep trying.