How do you replace a slave cylinder and remove transmission on a manual 1988 Ford F150?

Its going to depend on 4wd or 2wd .. Start by supporting the truck on a lift or jack-stands

then removing the drive shaft it should be 4 12m 12 point bolts,

then remove any wires, cables or lines attached to the transmission such as the speedo cable/wire, clutch lines ect

then support the transmission with a jack and remove the cross brace holding the transmission if it is 4wd you may find it easier to remove the transfer case as well

then remove the bolts starting at the top of the transmission, before removing the last bolt make sure the transmission is supported well and remove the last bolt

breaking the transmission from the block can be tough but a pry-bar or a sturdy flat blade screwdriver will do the job once removed the slave cylinder can be removed from inside the bell housing