Hey , you can update your project to the latest version of the engine by first launching the latest version of the engine from the UE4 main splash screen (the one with the link to the Marketplace and Library).
On the left side of the main splash page just select the latest version of the engine from the big yellow drop down then click it to launch - Once it’s launched you will see all of the projects, those which are on older builds will be greyed out. Just click on one of them then click OPEN and it will ask you if you want to convert the project in it’s place or make a duplicate for the update which i recommend.
will copy and convert all of the files to the new build.