I think I pulled my right quad doing hack squats. It hurts at the very top "point" of the muscle, especially when I move my leg in like a quick "kicking" motion (lifting at the hip). When I exercise, it actually loosens up and functions appropriately, but hurts when I'm done - especially the next day when it stiffens up. Been going on for about 3 days.
 
What is the best way to get through it?
 
Should I  stop hacks for a while, and substitute some other leg exercise that doesn't seem to stress it, or reduce weight but keep working it so its tsays loose?.
 
In the mean time and on my off days I'm stretching it as much as I can and taking care of it.
 
Anything else I could do to help it recover quickly and effectively?

1- Stop doing anything that hurts it

2- Start stretching (no discomfort stretches)

3- Give it time to fully heal

It feels better when you do the movement because you are esentially stretching it out (with weights).  It feels worse later because it's not healed and now you've worked it and possibly made more micro-tears (that is part of building muscle.. breaking it down to rebuild).

Anyway, I'd lay off.  Warm-up and then stretch.  Don't stretch a cold muscle.  And off the weights for a bit so you can recover.

A week or less should do it depending on the strain.

If you continue to work it, you could up with a much bigger injury or a nagging pull that never seems to recover.