Change Search Service Account and Remove old topology in SharePoint 2013

These are some post configurations related to search service in SharePoint 2013.

Change Search Service Account

1. Open SharePoint 2013 management shell as farm admin
2. Run the following commands

$password = Read-Host –AsSecureString Password

Set-SPEnterpriseSearchService -IgnoreSSLWarnings $true -ServiceAccount domain\searchsvc  -ServicePassword $password

Remove Old topologies

1. Open SharePoint 2013 management shell as farm admin
2. Run the following commands

$ssa = Get-SPEnterpriseSearchServiceApplication -Identity "SSA Name"

Get-SPEnterpriseSearchTopology -SearchApplication $ssa

Then just copy the GUID for inactive topology and run

Remove-SPEnterpriseSearchTopology -SearchApplication $ssa -Identity  620f2d33-08fd-4d3a-95ed-a3ed7cda130f

Then enter (Y)