Bubble Bags 20 gallon - What to do with last bag?

Ok, so I have the 4 bag kit and the first three were no problem, except for rinsing them out. Now I'm down to the last bag which is 20 micron and it's heavy as shit, and on top of that, i've been holding it for about 40 minutes! Anyone have a better way of doing this shit? I feel like I need to drill a hole in the bottom of the 20 gallon rubbermaid and just let it do its thing, instead of holding this heavy fucking sack. Anyone have ideas? I don't think I will ever do this again if someone doesn't have an easier way of doing this shit. I was so excited to get these things too....

you need to hold the bag up higher ,,maybe even over you head. and try to do sqwats this helps sometimes...no jk lol,, i know shit takes for ever, well worth it, not that i have ever done this.