urgent reuired Articleship transfer procedure

I have completed about 21 months training under my ca which is partner in the firm,, now my ca leave the firm,, what should i do,, whether i can go along with him or remain with another partner in the same firm,,
Which is the easy procedure from the above two?? Also when to do and how to do formalities so that my articleship and final attempt does not suffer,,
Please give some suggestions.
Thanx in advance