You don't need to re-install TeamPulse to change the account used for the IIS app pool or the integration service. Follow these steps to change the account in IIS:
1, Open IIS Manager and expand your server
2. Click Application Pools, find the one named TeamPulse_APP_POOL, and select it.
3. From the menu on the right hand side click Advanced Settings...
4. Find the property named Identity and change it to some account that has access to the DB.
After changing the account the app pool should recylce on its own but you can recylce it manually or reset IIS just to be sure.
If you need to change the account used by the integration service, follow these steps:
1. Open the "Services" snap-in (hit Windows key, type Services).
2. Find the TeamPulse Integration Service, right click it, and select Properties.
3. Go to the Log On tab, change the account, and click OK.
4. Restart the integration service to be sure the new account is being used.
the Telerik team