Is it permissible to change clothes in the mosque and remove one's trousers, thereby exposing one's 'awrah, if there is no one else present?

Concealing one's nakedness (awrah) is obligatory during prayer, in front of people, and in private according to the majority of jurists, except when there is a need, such as bathing. If it is possible to avoid exposing the awrah in the mosque by not undressing or by going to another place to change clothes, then a Muslim should not expose his awrah in the house of Allah without necessity, because it is different from other places. However, if there is no place other than the mosque, it appears that there is no objection due to necessity, and changing clothes is one such necessity. Concealing the awrah in private is required out of modesty before Allah and His angels. It is obligatory according to the Hanafis, Shafi'is, and Hanbalis, and recommended according to the Malikis, unless there is a need.