If you have more than one language installed and enabled in your X-Cart store, you can switch your store’s Admin language using the language selector in the header of your store’s Admin panel:

switch-admin.png

If you do not see the language selector in the header of the Admin panel, then probably you do not have any languages other than the default one enabled in your store.

Go to the Store setup -> Translations section and check if any languages except for the default one are enabled:

lang-enabled.png

If the necessary translation is missing install the related transaltion module as described in Installing language packages.