can i switch over to rogers from a bell phone if the bell phone has no sim card?

Even if the bell phone has no sim card if the phone is locked with the network then you need to unlock it to use the phone with other networks.To unlock you can approach Theunlockarena.com and remove the network lock very easily.You need to specify the mobile make,model,country,locked network and based on the availability you can get the unlock service along with free instructions.Once unlocked you can swap networks.