Configuring NAT: Many Private to 1 Public Address Translation

Configure static route on the remote router stating where public addresses should be routed.
Router(config)#ip route 203.189.xx.0 255.255.255.255.248 s0/0

Define a pool of usable public IP addresses on your router that will perform NAT (optional).
local(config)#ip nat pool NAT 203.189.xx.2 203.189.xx.2 netmask 255.255.255.248
NAT-Name of of pool(Any name will do)
203.189.xx.2-Start of pool
203.189.xx.2-End of pool
255.255.255.248-Subnet Mask

Configure an ACL that will identify which private IP addresses to be translated
local(config)#access-list 99 permit 10.10.10.0 0.0.0.255

Option 1: Link the ACL to the outside public interface.
local(config)#ip nat inside source list 1 interface serial 0/0 overload

Option 2: Link the ACL to the pool of addresses. if you using the created pool
local(config)#ip nat inside source list 99 pool NAT overload

Define which interfaces are inside (Private Addresses)
local(config)#int fa 0/0
local(config-if)#ip nat inside

Define the outside interface (Public Address)
local(config)#int s 0/0
local(config-if)#ip nat outside