1.) Visit our secure URL: https://login.salesforce.com/packaging/installPackage.apexp?p0=04t58000000cC2e to install the package.
2) You may have to log in using your Salesforce credentials. You will be directed to the screen below.
3) Make sure to choose which users you'd like to install the GetAccept package for.
4) Click the Install button.
5) You will then be prompted by the screen below to allow callouts to the GetAccept API.
6) Check the check box to grant access and then click Continue.
7) Wait a few minutes while GetAccept installs within your Salesforce environment, then click the Done button.