Or if you don't fancy the TSOP solution or a replacement DVD you could try
this. It claims to trick the Xbox into thinking there's a DVD drive there when there isn't, so should work for a softmod - and you can probably do it without soldering!
However .... notice that further on someone reckons that it fails, so you might have to do some fiddling to make it work.
Edit: But
this one reckons that connecting pins 2 and 7 works.