Kenneth,
Here are some steps you can follow:
1) Copy the contents of the flexviewer-2.4-src folder (i.e .settings, html-template, libs, locale, src, etc)
2) Create a "Flash Builder 4.5" folder in the root of your C:\ drive (This is a preference as I don't like my projects buried in my user folder).
3) In Flash Builder File menu choose Switch Workspace > Other and browse to the "Flash Builder 4.5" folder you created in step 2.
4) Back in windows explorer (or my computer) create a folder in the "Flash Builder 4.5" folder and call it "FlexViewer2.4"
5) Paste the contents from step 1 in this folder.
6) In Flash Builder from the File menu choose Import Flash Builder Project... > choose Project folder > Browse and choose the "FlexViewer2.4" folder from step 4 and click finish.
7) When it Asks about what Adobe SDK to use (hopefully you have already downloaded the Adobe 4.1 SDK) choose 4.1. If not then click the "Configure Flex SDK" > "Find and download other versions of Flex SDK" > Download Flex 4 SDKs > Flex 4.1 Update Adobe Flex SDK (169 mb) > once it is downloaded then extract it to C:\Program Files\Adobe\Adobe Flash Builder 4.5\sdks\4.1.0 > back in the prefferences dialog choose Add... > Browse and C:\Program Files\Adobe\Adobe Flash Builder 4.5\sdks\4.1.0 > ok
😎 Copy the eSearch source folder (from the download you did of it) and paste it into the widgets folder.
9) Right click on the FlexViewer2.4 project in the package explorer and choose properties > Flex Modules > Add > Source > Browse > src\widgets\eSearch\SearchWidget.mxml > ok.
10) Repeat the add button and Source > Browse > src\widgets\eSearch\SearchWidgetFixedDG.mxml > ok.
and finally your done.