How do i change my skin in pe without jailbreak 또는 computer

i downloaded an app on my phone and i sended to PE minecraft

당신 can't

if your phone is android 당신 should get the skin stealer from the 구글 play not for IOS :)

당신 don't. If 당신 jailbreak your device, it means 당신 go against Apple's Terms and Conditions, so that just means they wont fix your device 또는 anything.