Jenna Dewan and Boyfriend Move Into Her New House on 39th Birthday

Jenna Dewan is trading in birthday cake and candles for cardboard boxes and dollies ... she's moving into her new digs as she celebrates 39 trips around the Sun.

Check out these pics of Jenna and her boyfriend Steve Kazee on her birthday ... no celebrations, just business as they move into her new crib in Los Angeles. This is 39.

The good news is Jenna doesn't have to do any heavy lifting ... she's got a hunky BF and some movers to take care of everything. Of course, it looks like she's still overseeing the whole process -- it's the birthday girl's day after all.

Jenna's been living with a Steve for a little while now, and we're told she recently closed on the home ... and Tuesday was the big move-in day.

As you know ... Jenna's locked in a nasty custody battle with her ex, Channing Tatum, with the parents going at it over daughter Everly's custody. Channing is asking a judge to lay out a detailed schedule for who gets their girl and for how long, including holidays, birthdays and work trips ... something sources on Jenna's side say was already figured out.