Solved! How. To switch my CDMA LGV30 into GSM simcard?

Solution
You actually can't do what it is you are wanting to do.

CDMA is one network and GSM is another. They are not the same, and are not interchangeable. So you can only use a CDMA phone on a CDMA network, and a GSM phone on a GSM network. This would be why you are getting the message.

For example, Sprint has a CDMA network and AT&T has a GSM one. This is why phones from one will not work for the other. You would need to either get a CDMA SIM (to go with your CDMA phone) or get a GSM phone (to go with your GSM SIM) to make it work.
You actually can't do what it is you are wanting to do.

CDMA is one network and GSM is another. They are not the same, and are not interchangeable. So you can only use a CDMA phone on a CDMA network, and a GSM phone on a GSM network. This would be why you are getting the message.

For example, Sprint has a CDMA network and AT&T has a GSM one. This is why phones from one will not work for the other. You would need to either get a CDMA SIM (to go with your CDMA phone) or get a GSM phone (to go with your GSM SIM) to make it work.
 
Solution
Yeah, they are the networks used by 2 major carriers/service providers here in the USA. Most of the other carriers actually just rent access to the networks owned by the those two. So all the carriers/service providers here run on one of those two networks. It would be so much simpler if it was all one. :)