To migrate a project from Bluetooth SDK 2.3.x to SDK 2.4.x follow the steps described below.
Install SDK 2.4.x via Simplicity Studio Package Manager
Go to Window->Preferences then select Simplicity Studio-> SDKs
Disable older BLE SDK versions
OPTIONAL - You may use different workspace for the new SDK projects. In this case you need to import the project made with previous SDK to the new workspace. For importing use the Eclipse built in importer. Go to File->Import.. then choose General->Existing projects into Workspace. Enable the Copy projects into workspace option.
Open the .isc file on your project folder with text editor.
Add the sourceSampleAppId: soc-empty line to the file.
Save and close the file.
Double click on the .isc file and press generate on the GUI. Wait until generation finished.
OPTIONAL – You may delete the excluded files from the project. These are grayed out by studio.
Open the main.c and remove the pre-processor directives start from #ifndef GENERATION_DONE
Now your project should build with the new 2.4.x SDK .