You can use the dumpwallet command in Bitcoin core to get all the private keys in your wallet. The quote below explains it.
the command is dumpwallet you can use it from the terminal and you must give it a full path, e.g.
dumpwallet c:\mykeys.txt
If you have set a password you need to unlock the wallet first. The below command will unlock it for 60 seconds.
walletpassphrase PASSWORD 60
They will be exported unencrypted(!) so be careful.
After you get a list of private keys you can download the electrum wallet, then import them into it. Follow the steps in the quote below to do that.
Download electrum 2.6.4 portable from here (because the latest 2.7 versions are buggy).
https://download.electrum.org/2.6.4/electrum-2.6.4-portable.exeCreate a new folder and copy electrum-2.6.4-portable.exe into it, then double click it to start the wallet.
An install wizard window should open. At the top of it select the "Restore a wallet or import keys" option, then click the "next" button.
Another window will open with a box in it that you can type your private key into.
After that click the "next" button and another series of windows should open. Leave each window's settings as they are and click the "next" button in each one until the wallet opens.
You can leave the password boxes blank, the electrum wallet can work without a password, and its password is not the same as your multibit wallet's password.
When the wallet opens it should sync within minutes and show your Bitcoins. You can use it to send them wherever you like.