Not really sure where to put this, so feel free to move it if necessary
***THIS WILL NOT WORK FOR BLOGGER ACCOUNTS***
1) First off, you need to create an account at insanejournal.com. GreatestJournal bit the dust, and not many people use DeadJournal, so IJ is your safest bet. If you're lucky to already have a JournalFen account (or know a paid user who can request one for you - they've suspended new free accounts), then this will work also.
2) Once your new account is created, then you need to
Download LJ-SEC3) After you install the program, run it.
4) This screen should pop up

Enter in your LJ user name and password.
From this point forward I'm borrowing the tutorial from the LJ-SEC website, since it explains it pretty well. Before you proceed, please note the following.
* User comments cannot be transferred
* Custom security groups *probably* will not transfer properly. (You can try, but it probably won't work well.)
5) Check all the posts in the bottom box you want to transfer over.

6) From the "Journal" entry, select "Repost checked entries to another journal"

You can also select the repost button on the side of the main screen:

7) You will be presented with the following popup:
]

8) Enter in the information as follows:
* USER NAME: The login name of the new journal.
* PASSWORD: The password for the new journal.
* COMMUNITY: If you are subscribed a community and have filled in a login, hit "Get a list of subscribed communities". This will grab a list of communities you have access to. You can then select a community that you manage. Note that if your user name and password is invalid, you cannot grab a community list. You are not allowed to process communities that you are not subscribed to.
* SERVER URL: The address of the Livejournal-compatible Server URL. By default, the URL is what you use to login (which is probably Livejournal), but you'll need to select the insanejournal.com entry
* ATTEMPT TO TRANSFER CUSTOM SECURITY SETTINGS: By default, any journal entry that uses a custom security group is transfered over to the receiving account as a friends-only post. You can *try* and transfer your security groups with this setting, but it will only work properly if the security groups were created in the same *numeric* (not alphabetic) order on both accounts. (Maybe not even then.) Use this setting with caution.
* ATTEMPT TO TRANSFER METADATA: LJ-Sec will normally attempt to transfer extended properties, such as mood, icons, tags, etc. You can disable this if you run into problems.
* BACKDATE ITEMS: By default, items will be posted as back-dated. This is standard practice for posting historical journal entries, see this FAQ for reference. You can turn off this option, but Livejournal *will not allow* a post to be made if there is one dated in front of it. Turn off this option only if the receiving journal is blank, or all posts in the receiving journal are behind the journal entries you are transferring!
* SAME SERVER DUPLICATE POST PREVENTION: By default, LJ-Sec will prevent you from reposting journal entries on the server you are logged into. For instance, you can't by default post your Livejournal entries back into a Livejournal account. Accidentially double-posting on your own journal therefore is discouraged. There may be times that you wish to do this (for instance, if you are duplicating posts in another journal on the same server, or if you are restoring a deleted post). If so, turn this option off and you will be allowed to post on the same server that you are logged into.
9) Click "Begin reposting". LJ-Sec will confirm that you want to transfer entries.
10) Wait. Depending on the speed of your internet connection and the number of posts you're transferring, this can take anywhere from 5 minutes to an hour.
Your journal posts should be transferred over to the second account, and you don't have to worry about your journal disappearing overnight.
Hope this helps.