EB3 to EB2 ..steps after I-140

[sadboy]

I applied in EB3 and then changed employers.

My current employer filed a new petition for me in EB2.

My Question is

How long does it take to get the GC after I-140 is cleared.

The lawyer hopes to capture my EB3 priority date and apply it in EB2.

Any insight would be highly appreciated.