Oversize DB restore to SQLExpress
You should be able to just do the restore. Did you try it?

SQL Server will create the mdf and ldf files for you, with the same size they had when the backup was produced. And if the backup came from an express, then it shouldn't be possible to have a more than 10 GB size mdf - and there's no restriction on the ldf.

So just try the restore command (possibly using the GUI) and if it doesn't work, let us know what command you executed (you can script it in SSMS) and the error message(s) you got.