We are trying to replace an old fashioned bathroom sink and I mean old to a new pedestal sink. Is this a problem should we call a plumber? Someone told us gases could come out of it if we don't do it right. Please someone

Unless you or the person helping you is a professional "handyman" I suggest you hire a plumber to do this.

I found this great site that shows step by step what to do to install a pedestal sink. But even that site says if you have a wood vanity and want to replace it with a pedestal sink you should hire a licensed plumber. The location of the drain and water supply lines is commonly lower than what you’ll need for a pedestal sink. If so, you’ll need to open up the wall to replace the plumbing. Also you’ll need to install blocking between studs that the sink will screw into. This could take days plus the wall will need to be re-finished before installing the new sink.

Well, here are the steps and hope they help:
Pedestal Sink

P.S. Nice name

"georgia....georrgggiaaaa...the whole day through..." Sorry ladies just couldn't resist singing that one!

Don't get any wild ideas Kewl