How to safely remove pump chuck from Schrader valve
Ripping off the valve is a pretty rare occurence I think. If you manage to pull the valve off or even just spring a leak while removing the chuck then the inside of the rim (where the root of valve connects to the innertube and hits the inside of the rim) could be too sharp or the protective rim tape could be damaged or mis-aligned. This is the first thing I'd check.

Beyond that I think the top voted answer here to this almost identical question for presta valves is good concrete advice.
I would suggest you:


Make sure you unlocked the chuck properly.
Just pull straight away from de valve to get the chuck off (no twisting or bending or wiggling)
Be mindfull of the amount of force you use (both to avoid pulling the valve off, and to avoid slamming your hand into the spokes or something else as the chuck comes loose.