Detailed Steps for extracting a Lot Description using SimPE:
1) Run SimPE. Open the File menu and choose Open then navigate to where your game files are stored, for example:
\My Documents\Electronic Arts\The Sims™ Castaway Stories\Neighborhoods\00000000
2) Select the neighborhood package which contains the lot which you wish to copy. In the Sims Castaway Stories, N001 is the Shipwrecked and Single story neighborhood, Felicity Island, and N002 is Wanmami Island. In my example, I navigate into the N002 folder and open N002_Neighborhood.package.
3) In the Resource Tree in the top left pane, select "Lot Description".
4) In the Resource List in the top right pane, select the lot which you want to copy.
5) Right click on the lot and select "Extract...".
6) Create a new folder on your hard drive and save the extracted files.