904 trans ?

I know I havent been on in a while (Life got the better of me for awhile) but Im back with a ? for anyone that has rebuilt a 904 trans. I picked up a brand new reverse-low band as well as a brand new front seal the other day for 9 bucks for the pair. Is it possible to just replace the reverse band without having to take the whole trans apart? Like in this thread http://www.forabodiesonly.com/mopar/showpost.php?p=1359026&postcount=41
I see that just the front of the trans is apart when he replaces the band but I cant really tell if there are a bunch of parts before that or what...I just moved into a new house with no hill and its a $380 fine for driving through the yard (Got 1 warning already). I want to replace the band either today or Saturday so a quick response would be amazing. Thank you for any help or advice. I cant afford a full rebuild atm so the reverse band will have to do until then.