There's usually no need to remove the cover on that pump style. Disconnect both ends of the squeeze tube, and use the prime switch to remove and install the new squeeze tube.
This could be a matter of preference. I personally find it annoying as hell to try to put the chemical line into a squeeze tube that's still on the pump. Easier to take the tube right off the pump where I have lots of space and then just put it back on.
Had a delightful disagreement with my new supervisor about the importance of tube lube. Nobody at the company im currently working for uses it and im now an outcast for not changing a tube without it.
If the company is charging for the squeeze tubes, then maybe they just want to generate more revenue. Otherwise, it extends the life of the squeeze tube and should be used on most peristaltic pumps.
these new "low-temp" machines use incoming warm water at around 130°F. They have no internal heaters because the 3 chemicals are able to work at low temp and sanitation is done with chlorine alone, not hot water needed! Cheeper machines with quick run cycles...