How to use saved sims in cas while playing, sims 3?

Edit in CAS is to change the sim you're currently playing. 

What do you want to do with your savedSims ? Replace an existing Sim with one of the bin ? I don't think that's possible.

the only way to use sims you have saved in CAS is to go to edit town if the sim is in the libiary then you can add them to the household you already have or in edit town CAH (create a household ) then in CAS find the sim you saved tick accept and add them to the household your already playing you can have up to 8 sims living in the one house other than that as crin said it's not possiable to do so from edit in CAS

Well, it all started when I wanted my two men to have a child together, so I changed one of the mens sex to woman, but now I can't change him back to a man without changing his appearence. ☹️

and you want your original male back ?

Excatly ☹️

hmmm the only thing i can think off is you have those sims in your libiary start a new game move those two in to a new house then in edit town move the sim you want back out of the house save him to the libiary then go back to the game you normally play then in edit town move him back in you can make a story out of it as he will have to get to know everyone again the story could be like he went for a walk one eveing and aliens took him but when the aliens brought him back he didn't know where he was or remeber anyone but a friend found him  he was afraid at first becaus esomeone kne whim but he didn't know who he was couldn't remeber his name or anything but everyone that kne whim helped him slowly remeber things well you get the picture

i'll be back later to check back here