I'm no expert in modding. I put a Solderless chip in my Xbox and it worked until I moved a couple of times and did something to brick it*. Nevertheless, there's a lot of websites out there with information on Xbox modding (check out
this page).
But if you're not sure where to go, your best bet would to contact someone who, for a fee, will mod your Xbox for you (there may be a couple of members on this forum who perform this service though I don't have specific names). You may want to run a quick forum (especially on Buy/Sell/Trade) to see if anyone has an offer out there.
(*EDIT: This thread inspired me to take a look at the issue with my Xbox and after looking up some info, I was able to fix it - albeit without the mod.)