Click settings in the main menu
You can set a temporary location, by selecting the 'GPS location' option, on the left, and clicking save at the bottom of the page. If you are not on a mobile device (with a GPS chip), this relies on your ISP setting a correct location for the internet connection you are using, (which they usually do). This lasts one log in, (though it holds over when you log out until your next log in, when a new GPS location is sought).
To set a default location:
Click CHOOSE below the location field, top(ish) left
A map window will pop up. You can zoom and move around the map and click/tap to set your location. (Tip: in the text box, type your country, city, state, street or postcode/ZIP code to quickly jump there.)
Finally, click the 'select this location' button.
This will take you back to the settings page where the location you just selected will appear. To save the new location, click the 'Save updates' button (you may need to scroll down).
Things like the 'nearby' search in the main menu will now work from this location. You will also show up in other member's searches of this location, if they match your preferences. The GPS location will be used in preference to this set location unless you deactivate it. You may need to de-select the GPS option on the log in page, if you have it selected.
To maintain your privacy, other members do not see your exact location on a map (unless you specifically send it to them in a message), only a distance from their location and even then with a random inaccuracy of half a mile for home users. Mobile/GPS distances are shown more accurately.
You can remove the location from your profile at any time. Click settings in the main menu, as above, but instead of clicking CHOOSE, click RESET, then scroll down and click the save updates button. This will stop some of the sites functions working, like the nearby page. Other guys won't see you as much, and you won't be able to find them as easily.