bedrock already supports all of java edition's skin formats. you don't need to change anything :D

If you're playing Bedrock on PC or mobile, you can take the image file that you used in you Java skin and follow what the other guy said. If you're playing on consoles, there is no way to use a custom skin.

you dont really need to change it to anything, skins work for bedrock and java, they load in the same, if you want to use your skin on bedrock do this



(if your on computer)

load into minecraft > go to skin menu > go to classic skins > there should be a gray skin at top, press it. > select the file you want off your computer.