Ok I searched for the answer and did not find one for this specifically. I do understand how leyton hightower works just an interaction with bastard. Obviously he would not lose his power Icon but the question is would all the other attachments fall off? Or because he is immune to opponents attachments the effect on it of discarding the other attachments on him would be canceled by effectively blanking the attachment when they tried to put it on him. Just trying to understand that interaction. thanks in advance.

Leyton's text is:

No Attachments. Renown.
Leyton Hightower cannot be saved.

Maester characters you control gain: "immune to opponents' events and attachments."

So first off I assume you mean putting a Bastard attachment on a maester character that your opponent controls who also has Leyton in play. Characters with immunity to attachments are not immune to the discard effect of Bastard because it does not target the character. When played on a Maester it will knock off all the attachments that was currently on that character. Being immune to attachments, they would not loose the POW icon and they would be immune to the effects that say you can't play attachments on that character. 1 important note on Bastard though is that it limits attachments from being "played", but not "put into play" such as from the Maester's Path agenda. So even without Leyton in play, they can still move chains from the agenda to that Maester with the Bastard attachment.