Scenario 1: Changing an EIP for an ECS:
1- Unbind an EIP:
a. Log in to the management console.
b. On the console homepage, under Network, click Elastic IP.
c. On the displayed page, locate the row that contains the target EIP, and click Unbind.
d. Click Yes.
2- Assign an EIP:
a. Log in to the management console.
b. On the console homepage, under Network, click Elastic IP.
c. On the displayed page, click Buy EIP.
d. Set the parameters as prompted.
e. Click Next
3- Bind the new EIP to the ECS:
a. On the EIPs page, locate the row that contains the target EIP, and click Bind.
b. Select the desired ECS.
c. Click OK.
4- Release the EIP that has been replaced:
a. Release a single EIP:
i. Log in to the management console.
ii. On the console homepage, under Network, click Elastic IP.
iii. In the EIP list, locate the row that contains the target EIP, and click Release.
iv. Click Yes.
b. Unbind multiple EIPs at a time:
i. Log in to the management console.
ii. On the console homepage, under Network, click Elastic IP.
iii. In the EIP list, select the EIPs to be unbound.
iv. Click Unbind above the EIP list.
v. Click Yes.
Scenario 2: Changing an EIP for a Load Balancer:
1- Unbind an EIP:
a. Log in to the management console.
b. Click Service List. Under Network, click Elastic Load Balance.
c. In the load balancer list, locate the target load balancer and choose More > Unbind EIP in the Operation column.
d. Click Yes.
2- Assign an EIP
3- Bind the new EIP to the load balancer:
a. Log in to the management console.
b. Click Service List. Under Network, click Elastic Load Balance.
c. In the load balancer list, locate the target load balancer and choose More > Bind EIP in the Operation column.
d. In the Bind EIP dialog box, select the EIP to be bound and click OK.
4- Release the EIP that has been replaced.
Scenario 3: Changing an EIP for a NAT Gateway:
1- Assign an EIP.
2- Modify an SNAT rule.
a. Log in to the management console.
b. Click 
in the upper left corner and select the desired region and project.
c. Click Service List in the upper left corner. Under Networking, select NAT Gateway.
d. Switch to the Public NAT Gateway page.
e. On the displayed page, click the name of the target public NAT gateway.
f. On the SNAT Rules tab, locate the row that contains the SNAT rule you want to modify.
g. Click Modify in the Operation column.
h. In the displayed dialog box, modify the parameters as needed.
i. Click OK.
3- Modify a DNAT rule:
a. Log in to the management console.
b. Click in the upper left corner and select the desired region and project.
c. Click Service List in the upper left corner. Under Networking, select NAT Gateway.
d. Switch to the Public NAT Gateway page.
e. On the displayed page, click the name of the target public NAT gateway.
f. On the public NAT gateway details page, click the DNAT Rules tab.
g. In the DNAT rule list, locate the row that contains the DNAT rule you want to modify and click Modify in the Operation column.
h. In the displayed dialog box, modify the parameters as needed.
i. Click OK.
4- Release the EIP that has been replaced
