Drain Seal in Kitchen sink

If you mean for your basket strainer(s), you need to unscrew the jam ring under the sink and pull the basket strainer body out through the top. Then clean up all the old sealant (rubber, silicone, plumbers putty, whatever). Make sure the opening in the sink bowl and the outside of the basket strainer are very clean, dry, and free of any moisture or oily substances and either use fresh plumbers putty or a heavy bead of silicone (about 3/8 to 1/2" bead) laid around the hole for the bowl drain and carefully place the basket strainer back in the hole, tighten the jam ring back up on the basket strainer until the basket strainer will not move at all, carefully wipe up the excess caulk material around the drain in the bowl, let the assembly set for 24 hours before running any water and you will be ready to go.