I have always had to phone the IT department and get them to log them off remotely, usually because someone went home with the DB open and the terminal locked when I want to do some work on it.
You could look at having a timed event that would alert the user and if no response then shut down. If it is only the forms your are editing then I suggest you use a front end (Forms) and back end (Data) see help and splitting Database for more info.
I'm sure I had a sample database somewhere that does what you're after... will see if I can find it
One question tho: which version of Access are you using?
Currently I use 2013 - however splitting the database has been in every version I can remember from Office 98 - Under Database tools you will find the option to Split the database all links are auto generated for you. The tables are then linked from the Backend to the Front end, you can have multiple Front Ends editing the single Back End data. Ensure Edited Record Locking is set in your Database Preferences.