You are all right. If possible, loosen that lower damper rod bolt while the top cap is still in place and the spring is pressing down on the damper rod.
If the bolt turn turns and will not loosen, try an impact driver - or if you don't have one, smack teh wrench with a large mallet and sometimes that will crack it free.
If/when that still doesn't come loose, or the forks were partially dismantled already, that's when you need to use a tool to hold the damper rod still. Some forks need a special tool to match the odd damper rod top, but most work with a bolt. I use a length of steel tube with a Tee handle on top 0 drill a hole through the tube and use a screwdriver or weld a cross tube in place. Then weld a suitable hex nut to the bottom of teh tube to lock the damper rod.
I had to make one the other day for a buddy who had partly stripped his GS1000E forks and it took all of about 15 minutes to make. But I was lucky that I had a spare set of dismantled identical forks to measure what size nut I needed.
Other time you have get away with a long extension and a couple of nuts on a bolt in the socket.
I have even seen a broom handle whittled down at the end and rammed into the top of the damper rod.