Changing server in SIPDROID

[Pothik]

Hi,
I got the source code of sipdroid following the link ::
http://code.google.com/p/sipdroid/source/checkout
using the command :: svn checkout http://sipdroid.googlecode.com/svn/trunk/
sipdroid-read-only.

sipdroid uses pbxes.org to tunnel voip calls. But i want to configure
this and use different sipserver to make voip calls.

As a new comer in this field i need help and suggestion about how to
change this server.

Thanks