It very much depends on what type of gel nails you have on. There are 3 basic types of gels that can be applied to your nails. As an informed consumer you really should know which type of gels you are wearing.
Hard Gel - the longest available type of gel and must be filed off. It is impervious to acetone - it can not be soaked off. This is one reason these types of gels became very popular. They satyed beautifuly shiny from the day you had them applied until you returned to the salon for a fill.
Soft Gels - also called soak off gel. The can be soaked off, but there will beed to be some agressive filing to "break the seal" before you soak. Often a hard gel topcoat was used and you would need to file it off completely before soaking off the soft gel. It can take 20-40 minutes to saok these nails off plus the filing time. A qualified technician would be able to accomplish the task with no damage much quicker.
Gel polish - the newest type of gel on the market is much easier to soak off. Some brands you do not have to "break the seal", but most do need that done. Gel polish can be soaked off at home in usually 10 minutes. That us of course if you can get someone to "wrap" your other hand! Otherwise it would be 10 minutes per hand.
Soaking is best done the same way you would soak off a set of acrylic nails. See How do I remove acrylic nails safely? for more detailed information.