Where can make power cord be detachable for LS15

I like my Audio Research LS-15 pre-amp. I want to use a better power cord to replace the permanent factory power cord. It seems need remove the original power cord firstly, and make a hole to fit the AC Inlet. The work is hard to me due to I have not the special tools.
Where or which store could help me make it in Los Angeles area. Appreciate some one can let me know!