The basic advice is to do the Work and there is a lot of information about that in other threads on this forum.petite femme said:All that said, this advice you've been given is vague and doesn't really tell you anything about how to go about doing what's been suggested.
It seems unlikely that somebody else can remove that entity. One of my spiritual teachers did a sort of 'psychic surgery' to remove my attachment at one point and while it may have helped to speed up the process of removal, the entity still remained attached for about a year. In any case, it needs to be someone you really trust to do something like that as an external help and I think that doing the Work is necessary in any case to close the opening that is there.
Then again, there are probably different types of entities and some may be easier to remove while mine was quite 'sticky'. From what I've heard from other people who had to deal with entity attachments, doing the Work and raising one's 'frequency' through self-growth is what ultimately removed the attachment.