Change battery 2012 ford con transit keyfob

these "fobs" have a permanently charged battery, intending to last forever, think the demand is going to be a small amount of time~ DO NOT launder the fob, that may kill it~ have 3 additional keys made, cause forget to unload the pockets before laundering~ not sure one can replace just the battery, they are thoroughly integrated~ buy a fresh key, most appropriate~ yours is 10 years old already~