It can be done in about 30 min faster if it isnt cold outside and you have some help.
Here is the steps for the 8010/8120 that I have done.
First remove the top to get to the bottom easier.
You will need a pliers, 13 or 14mm (I think), 18 and 19mm wrenches.
Step one turn the key on, then raise the spreaders.
Then drop the access panel to the bottom to the bottom sieve, two "L" pin latches.
There are three bolts that hold the two top sieves in. Two on the out sides and one in the middle. Take them out.
18&19MM
Next we need to unlatch the linkage from the sieves. There is a quarter turn latch that needs turn to release the sieve. Might have to move the sieve open closed to release the pressure on the linkage. Reason key is in the on position.
Pliers may be needed
You can either wait and turn the key on before previous step your choice.
After disconnecting the linkage, lift up and pull out the sieves.
Now you have access to the bottom sieve. Same as the top for bolt removal and linkage from sieve disconnect.
To remove the bottom sieve slide it out the access panel, the rubber flap might catch on the sieve.
Take off the linkage with the 13, 14, mm wrenches.
Reinstall the top sieve, bolts, attach linkage, put up access panel, put down spreaders and do combine.
On the bottom sieve you may notice an adjustment on the sieve to make it open further with the motor. It takes a 10mm wrench to move. It allows the bottom sieve to use a different range with the motor. Kind of hard to explain I'll find a picture to show.
In the picture the bolt #13 is in a slot #2 or #12 to adjust the bottom sieve position relative to the motor.
Also shown is the quarter turn latches #3, and the linkage #4 that needs to be removed with the bottom sieve.