Transferring from NYC to LDN Office

Hey all, 

Hoping to get some advice / anecdotes. Little bit of background here to start: I've been on the sell side in a US Corp HY Sales seat for almost a year now and have loved my job. I have a very strong relationship with both my MD and Director and think I've done a pretty good job of providing value to the firm and to my clients (still waiting on my first bonus, I guess that'll really answer how well I'm doing). The shop I'm at is on the smaller side, but is a legitimate bank with offices globally and I'm thinking about putting in a request to transfer to London.

The move will be almost entirely for personal reasons. I spent a year of undergrad in Ldn and have always wanted to move back. Additionally, my significant other is an EU citizen on a temp VISA that runs up in June; she's secured a role in London (she has pre-BREXIT right to work, so no issue there) and will be moving there sometime in the middle of this year. We've been together for a while now and I'm confident she's someone I want to follow, but it also helps that I had a pre-existing desire to move abroad again.

I'm not really sure how to navigate this (i.e. when/how to do it). I visited our London office in late November and have kept in touch with a handful of ppl I met while I was there and its no secret here that I want to go back, however its not something that's really been discussed. I'm also not sure there's a role for me at my current firm in Ldn at the moment, nor if there will be one in the foreseeable future. I've thought about reaching out to headhunters there to float my CV around, as well as being more direct with my firm about my desire to move to the UK, but have yet to take any action.

Any advice anybody has would be greatly appreciated. Thanks a bunch.