What would you call easy?
There is nothing that will be a bolt in, unless you find a truck 3 speed, column, shift linkage, and maybe drive shaft.
Going from the stock 4 speed to a 3 speed is also not going to be much of an improvement, if that is what you are after, since functionally, your current 4 speed is a 3 speed with a granny gear. 2nd to 4th will be more or less like 1st to 3rd of a 3 speed. The primary benefit will be that it is lighter.
Swapping to anything other than a transmission that was available for the truck is going to require some degree of customization which may include cutting holes, adding a crossmember, altering the drive shaft length.
Lawrenceville, GA