...
The set protocols bgp neighbor peer-group command creates adds a peer to a peer group.
The delete protocols bgp neighbor peer-group command deletes command removes a peer to a peer group.
Command Syntax
...
Instead of specifying properties of each individual peer, you can define one or more peer groups and associate all the attributes common to that peer session to a peer group. A peer needs to be attached to a peer group only once, when it then inherits all address families activated for that peer group.
Note:
If the peer you want to add to a group already exists in the BGP configuration, delete it first, than add it to the peer group.
Example
• This example creates a peer group.
...