Well, there are several different models of step-up transformers that you could use depending on the cartridge you plan to use, so there's no one size fits all set of instructions that will cover absolutely everything.
In general:
1. Pop the resistors out of each RCA jack that go to pin 9 on each EF86 (leave them attached to the socket, just pop out the end sitting in the solder cup of the RCA jack).
2. Remove the 47K loading resistor on each RCA jack.
3. Reconnect them at terminals 2 and 17.
4. Install step-up transformers.
5. Wire step-up primary wires to each RCA jack.
6. Wire step-up secondary wires to terminals 1/2 and 16/17.
7. Install loading resistors as recommended by the SUT manufacturer and/or your cartridge manufacturer. You can load the primary or the secondary of the SUT relatively easily by either using loading resistors across the RCA jacks (loading the primary), or loading resistors between 1/2 and 16/17 (loading the secondary).
At some point I'll post some photos of my Eros 2 that has this installed. I had taken some a long time ago but I was unable to locate them.
