You can rebuild a 4L60E with a $20 set of snap-ring pliers and a flat-blade screwdriver. You'll also tear two input seals, score a pump bushing, and spend twice as long doing it. Here's the real tool list - specialty stuff you need, common stuff you already have, what you can fake when you have to.
Lip seal protector cone (input shaft seal install). Pump bushing puller/installer. Servo cover compressor (yes you can use a spring compressor but you'll cock the cover and tear a seal). Sun shell holder. Reverse input drum tool. 2-4 band servo pin gauge (sets correct band travel = correct shift feel). Direct clutch hub bushing driver.
View on ShopifyHeavy-duty snap ring pliers set. Thrust washer measuring set. Magnetic base dial indicator. Torque wrench (1/4", 3/8", 1/2" coverage). Bearing/race installer set. Standard mechanic's tool box otherwise.
View on ShopifySun shell can be held with a strap wrench but it slips and pinches your fingers. 2-4 band servo pin can be measured with a micrometer (sub-3 thou tolerance). Lip seal can be installed without the protector cone if you're VERY careful — but you will tear one within 5 rebuilds.