Complex sentence: However, since viewing a video requires downloading it to the computer, their software merely makes saving videos difficult, not impossible, as a number of solutions, including external software and bookmarklets, have been developed.
Split into simpler sentences: However, since viewing a video requires downloading it to the computer, their software merely makes it an inconvenience to save downloaded videos on the computer. A number of solutions to this problem, including external software and bookmarklets, have been developed.