You're talking about 5h videos. The replaymod does not produce videos when recording, it creates replay files which are fundamentally different from videos.
In case you meant replay files, the replay editor can stitch those together (note that this does not yet work perfectly every time). However I strongly suggest you not to stitch them together as jumping in a 48h replay file is extremely slow.
In case you actually meant videos, your video editing software should do that, though I'm not sure what you plan to do with an 48h video file.