@smithcreed I think you will have to install the required packages in your R installation. Maybe try and use RStudio which makes it easier to handle such things.
Also you might want to familiarise yourself with the handling of KNIME and R in general.
If you absolutely need RTools to compile packages (which should not be necessary in general) there is this older entry about that.
Also there is this collection about KNIME and R you might explore. Some topics are somewhat special.