The directions from Bell Meadows should be just about the same as from Crabtree, except you are committed to the low route which would be preferred anyway. There are two standard ways in. Both go from Bell Meadows/Crabtree to the West Fork Cherry Creek. One route then takes the old route to Rosaco Lake--which is a good first day destination, and then follows the old route/granite ducks across to Pingree and down to Big Lake.
The second route continues on the Buck Meadow Trail toward Wood Lake until just after it fords Buck Meadow Creek, then takes an old stock trail south to Pingree and then Big lake.
I have two trip reports, each of which took a different route.
The stock trail is described here:
http://highsierratopix.com/community/vi ... co#p136477
The Rosaco route is described here:
http://www.highsierratopix.com/communit ... =1&t=14590
There are other ways too. Some come in to Hyatt cross-x from Bourland Meadows, and it is not far from Hyatt to Big. You can also come up to Big Lake from Cherry Creek Canyon if Cherry Creek is fordable--but that is not a direct route and is a long trip from Shingle Springs.
Probably the fastest way is the Rosaco route provided that West Fork Cherry Creek is crossable, and provided you don't mind a little route finding as you try to keep roughly on the track of the old trail that comes and goes.
It is a magnificent setting for a lake.

- Big Lake from the Pingree direction