I moved my Ethereum out of my coinbase account and to a cold wallet/address. My question is, how do I get it out of cold storage so I can trade with someone?
I recommend you to use MyEtherWallet to send your ethers.
On every exchanges you can find an address used to received your ethers. Just send ethers to this address. ( It is not the address that sent you ethers to your cold wallet )
It will not be really different than the process you followed to withdraw your ethers in the first place. Make sure address is correct(0x...), amount and leave the data field empty. Here a good guide with screenshots how to use MyEtherWallet
Always test before with very small amount before
Alright guys, I have found the answer to my question, I am posting it here so if anyone else has the same question, they can find the answer. I was able to find an app that lets me import my cold storage address using either the private key or the mnemonic phrase called imtoken. After installing the app I gained access to my ETH.