To get to your pricebook from the S2K main homepage - Click the PRICEBOOK section > PRICEBOOK MANAGEMENT bubble > Click theMANAGE PRICEBOOK link.

Your pricebook page will open. Where you can the use the search tools available to locate a group of the items you are needing to change retail for:

You can also use the ADVANCED SEARCH feature to help group the items:

Use the search window to filter your search further, then click OK:

You will then see the advanced search work with the main search to locate the group of items:

Once you've filed your search use your CONTROL key on your keyboard to select multiple items intended for a price change. Hold the control key and select through the list - you will see a black dot appear next to the selected item:

Click Batch Edit to edit the retail of selected items:

Change the retail price, make sure the change scope is for only the items you have selected, then click OK:

The changes will be reflected in the pricebook and you will need to open the pending pricebook window page and send the changes to the POS.