First let's verify you have the problem this tutorial is designed to fix. These images show what a bad / worn out BCG600SIL impeller looks like and then what a good impeller looks like. If your grinder has similar wear to the bad picture (and is jamming) then this tutorial will be able to help you.

Unplug your grinder. Remove the hopper and take the upper burrs out. Empty out any coffee grounds (An air gun or vacuum helps) and then inspect the impeller blades.

If the impeller can fit through the hole (ie: be removed just by taking out the lower burr) then it definitely needs replacement. A good impeller should not be removable without dis-assembly and the tips of the impeller blades should not even be visible. If yours is between bad and good, make a judgement call using the pictures as a reference.

FYI: If your impeller is made of stainless steel rather than plastic (like the picture), your model is NOT the BCG600SIL. In that case, you likely have a different model with significant design changes. Stainless steel should not wear out and so your problem is elsewhere.