its not easy but its the exact same way you do the 5S-FE, 1MZ, 3MZ, 2JZ, and several other toyota engines. you can look for a detailed guide for those.
in a nutshell there are 2 SST (special tools) that you can use. One grabs the cam shaft and pushes down on the bucket. the other helps pop out the shim. I have tried to use them and its not easy.
What I ended up doing was just taking out the camshaft and changing the shims. I also replaced the water pump and timing belt.
2001 Celica GT-S Turbo1997 Supra TT 6speed1997 Celica 3MZ/1MZ swap1990 Celica All-Trac