How do i remove malware on my android if the malware has admin

[AC Question]

I have an older pantech flex and it was on 4.1.2 and couldn't run a few newer things out here so recently I downloaded zip files for 4.4 on my pc, got the apks swapped them to my phone and solved my google search popups aswell so I did all of it right with the help of sites like this and the phone works fine, but I mustve picked up some malware. I found an app on my phone that just popped up, I try to delete it and it says it has admin priviledges I go to take it away from it and upon hitting settings I'm redirected to a screen with a little android guy and a message says verbatim "update now PLEASE READ! Do no turn off or reboot your phone during update. please try again later" so of course I go to my anti malware, it identifies it immediately says uninstalling and then bam it has admin priviledges . So it has admin, I cant take that away without going to settings. well it basically took settings over with a pop up. I'm stuck. please help.