File size too large to backup

I'll start by saying our file size is 2GB and I am no pro at Reckon Hosted...

I can't seem to clean up data as it must do a verification/rebuild first which never completes, it just times out. 
I have tried to do a normal backup at home, after 19 hours it got to 90 something % and then failed AGAIN.
I called tech support last Thursday, the woman managed to do a temp backup but told me I need to complete a verification of data before I can upload the backup onto the new version, however, like I said, I cant do this. I tried to upload the temp backup onto the new version however it wont accept the tmp file type. 
Its a viscous cycle of need to do 'this' but can't without 'this' and I can't do any of it. 
Q1. Is there a manual way I can clean up my data to reduce file size to hopefully backup as normal?
Q2. Or am I better of creating a new company file and bringing over only a few years worth of data? Or will I need to do a back up to do that also?
I can't seem to find any answers that don't require a backup. 
I have been trying to do this for the past week, tech support was most unhelpful, they could tell how frustrated I was getting and offered no resolution. I have tried calling tech support 4 times this morning and the automated message says the center is at capacity and cannot take my call.
Completely at a loss of what to do!
Have included a snapshot of our product info for an idea of our file size. 


ANY Help at all is much appreciated.