How to Update Sun Cult yourself (Windows 7, Firefox 4) Rated 5 out of 5 stars
For Windows XP and Firefox 4, go to https://addons.mozilla.org/en-US/firefox/addon/sun-cult/reviews/230463/ but change "3.5" to "4.9" in step 10 and don't forget to switch on the Add-ons bar (see step 16, below)
1) Go to Computer > Tools > Folder Options. Select the 'View' tab, and uncheck 'Hide extensions for known file types'.
2) Go online and find the Sun Cult page in Add-ons for Firefox.
3) Right-click on the 'Add to Firefox' button and select 'Save Link As...'. This will enable you to save the Sun Cult XPI file to your desktop.
4) Rename the file you have just saved by right clicking on it, selecting 'Rename' and replacing ".xpi" with ".zip". You will encounter a 'Rename' warning; just click 'Yes'. You have now changed change the xpi file into a ZIP folder.
5) Open the newly created ZIP folder by right-clicking it and selecting 'Open with' > Windows Explorer.
6)Right-click on the "install.rdf" file and remove it from the ZIP folder using Cut and Paste (don't just drag and drop). Anywhere outside the folder will do.
7) Right-click on "install.rdf" and select 'Open'. A dialogue box will pop up. Check the 'Select a program from a list..' option then hit 'OK'.
8) Select 'Notepad', uncheck the 'Always use the selected program to open this kind of file' option, and then hit 'OK'.
9) You are now in Notepad. Make sure that your text cursor is at the very beginning of the document's text and then go to Edit > Find
10) Enter "em:maxVersion=" (without quotation marks) into the 'Find what' box and then hit the 'Find next' button.
11) You will be taken to a place in the document that says: em:maxVersion="3.5"
Replace 3.5 with 4.9 , then close and save the file.
12) Return the newly altered "install.rdf" file into the ZIP folder from which you took it (dragging and dropping is OK this time)
13) Rename the ZIP folder back to an XPI file
14) Open up a new Firefox window and drag and drop the XPI file into it.
15) Follow the normal add-ons procedure from there.
16) In Firefox 4 you need to switch on the Add-on bar in order to be able to see Sun Cult: from the new orange Firefox button (at the top left of every Firefox 4 window), go to Options and check the 'Add-on bar' option.
17) Now tidy up. Go to Computer > Tools > Folder Options. Select the 'View' tab, and check 'Hide extensions for known file types'.
18) You can safely delete any files that you have saved to the desktop
19) Have a well deserved cup of tea.