*elaboration* Merge Split DVD into Single disc

I guess I should have given more details with my previous post…

I have just begun using CloneDVD 2… I USE IT TO COPY UNPROTECTED, COPYRIGHT-FREE, PUBLIC-DOMAIN DVDs (such as live musical performances). I DO NOT USE IT FOR ANY ILLEGAL ACTIVITIES.

SO… to the issue at hand -

If I have downloaded files for a DVD that has already been split into 2 discs, and I want to merge these files back into a single disc, can this be done in CloneDVD?
If not, what software would I need?

Dvdshrink in reauthor mode.