How does the halacha require a woman undergoing conversion to prepare towards immersion in the mikveh? In what way is the required preparation similar or dissimilar to the preparation of a married woman towards immersion for rendering her tehora? And what about the laws of haziza in immersion leshem gerut?

A woman undergoing conversion in regard to Chaztiza should prepare herself for tevilla as a Nidda. (See Gerut Kahalacha chapter 4). Gmar Chatima tova