can i configure 2 (XBee series 2) modules using one explorer
You only need one. 
In order to communicate in Point To Point, you must configure each xbee to belong to the same NetworkID (PAN ID). XBees can only communicate with each other if they have the same network ID. Configure one, switch the xbee then configure the other (see here)

There are more advanced configurations that you can use (check this tutorial for extended information).