Screwed up garage door trying to replace bottom seal

So I wanted to replace the bottom weather stripping on my garage door this weekend. The garage door was installed in the mid 80s, so the bottom bracket seems to be an out-of-date part. Standard bottom brackets today are side mounted as pictured below, but mine covers the bottom of the door, so it has to be removed to replace the slide-in weather stripping.



I did a fare amount of research on Youtube and Google to properly do this repair, but didn't come across my particular bracket type. I wasn't aware that removing the bolts of this bracket and sliding it off allowed the spring loaded torsion cable to retract freely. Luckily my fingers weren't in the way, because these torsion cables can do serious damage if your hand is in the wrong spot.


I quickly learned these aren't meant to come off by amateur DIYers and I had both brackets retract up, but managed to pull one side back down and reattach it which was also a dangerous task. The other torsion cable snagged a few times on the way up and started fraying and unwound itself from the top pulley. I threw in the towel and contacted a repairman to come out and work on it, as I don't want to mess with the pulley, cables or spring and lose a finger over this. After researching more, it looks like the type of bracket I have isn't commonly used and the above left pictured bracket is commonly installed on modern garage doors which allows you to easily slip that rubber seal in and out.

I can't seem to find a better way to have gotten the old seal out and a new one in as the entry to slide the seal was under this bracket and it had to be moved. I'll surely fork out some $$$ tomorrow, but it's better to keep my fingers and lose some money over what was supposed to be an easy fix. Does anyone else have these older "full-cover" brackets?