You'd also need to set up whichever method you want to use to help get your items updated (i.e. ecom syndicator, file exchange, etc) - https://go.skugrid.com/sku-grid-ebay-repricing-options/
Then if you intend on using Sku Fetch & Wise Lister for the 2nd account, you'd log into sku fetch using the new sku grid credentials and configure your settings and you'd create a new wise lister account with another email address. Follow all steps to set up and connect the 2 - http://skugrid.freshdesk.com/support/solutions/articles/5000786550-quick-start-guide-for-using-wise-lister-sku-fetch
So in short, you'd be doing everything you did for your first sku grid account, but for the 2nd one now.