Need help designing HPF add-on

[shaaregeulah]

Hi all. I'm an electronics newb so please bear with me.

I'm putting together a DIY solid state mic pre from a kit that i purchased from FiveFish Studios called the SC-1. The pre I'm putting together also includes a second board containing input and output transformers, a Hi-Z input, as well as phase reverse and -20dB pad options.

All of the parts were sold in a kit form so I'm just putting it together and have no experience in designing or modding electronics, but I'm interested in adding a High Pass Filter to the pre. Specifically, I want to be able toggle between 60Hz, 120Hz and flat[off].

Am I reaching over my head or would this be easier than I think it is?

I hope someone could help. I've been bugging the designer/seller of the pre kit too much and was hoping I could find the answers here.

Thanks!