my peace lillies are not doing very well, i found tiny white bugs and little centipedes in the pot what can i do to get rid of them and what is the best way to care for them durring the winter months ?

I would repot your peace lily with all brand new soil, that way, you know your getting all the pest out in one shot. Use sterilized soil and add something like "Perlite" found at Walmart and Lowes for better drainage if need be. The pot should be no bigger around than an inch between the root-ball and inside of pot.
Winter care is about the same as summer care, but you'll want to keep it out of the line of fire of any direct high heat though. Water well,let it flow out the bottom and spill any excess that goes into the dish out.
Let the top couple inches dry before re-watering, you want "semi" moist soil at all times, so check the soil once a week or so..Don't over-water or let the soil dry out completely.
Bright light, no direct sun. Fertilize in the spring/summer months half strength.

Instead of repotting the whole plant to a bigger pot I put about 1/4th of it in another pot, and now its dieing. Can I save it?