[Amps] Lowering the voltage on a transformer

[Peter]

Hi

I just get my hands on a nice transformer but the volttage is too high.
The transformer is rated 4000/4500V 3800VA
I like to remove some secondary windings to go to 2500-2600 V

My question is:
Do I need equaly remove the windings on both sides?
1 side holds the "0"while the other side have the 4000/4500V tape

I have some pictures at : http://www.pi4cc.nl/temp/hsp/

Peter
PC2A