If you are an user with Music Collection (any version from 1.0.0 to 1.5.1) and wish to update to 2.0.0, that's what you should do:

1. Consider this: Music Colletion 2 is a MAJOR update. Therefore, MOST OF THE FILES will be overriden. That includes ALL LAYOUT FILES!! MC2 uses the new Layout for albums and songs (the same we have in this demo site). Be sure you have read this line before upgrading this version. If you had an old template, it will be overriden by this new one. Maybe you'll need some extra CSS styling, so you must asume that upgrading to 2.0 will take you some layout styling time.
2. Read again point 1. Seriously.
3. If you have a customized version of Music Collection, you cannot upgrade, as you probably know. So, no need to keep reading. You may want to contact us. Keep your current version, or the customization will be lost. Also, if you performed any code changes (on templates or core files), consider that those will be probably overriden. So that's up to you: we suggest you to keep a copy of your modified files, just in case you want to perform the same changes on new version. (Joomla Music Solutions Team does not responsabilize on code changes made by customers being lost on updating)
4. Read again point 2, if you were in that situation. We mean it.
5. Besides all that... don't worry much. Music Collection 2.0 is way better than any previous version. And it has no destructive effects on your database (that is, your music data). So no content will be lost or changed.
6. Prepare to upgrade. To perform test upgrades on test servers is always a good idea.
   
7. Check that your version is 1.5.1. If is not, find an update package till you have 1.5.1
8. Decide wich version do you want. There are two versions: Music Collection and Music Collection Community. What version is better for you?
1. Music Collection: Does NOT allow frontend content addition by frontend users. Therefore, if you want the music data on your site be added only by you, as an admin (or any other administrator), you should use this version. This is the way Music Collection 1.5.1 works, so if that's ok for you, and do not need frontend content addition, this upgrade package is for you
   
2. Music Collection Community: Frontend users can add content (artists, albums and songs). If you want this feature on your site, this is your version. Additionaly, you can download Community Builder and JomSocial plugins for this version, so each user can show his albums on its CB or JS profile page.
9. Download the file and install it. Joomla installer. You should have no problems.
10. Download JW Player plugin 2.0.0 and install it.
11. Download JW Player module 2.0.0 and install it (if you want).
12. Download CB or JS plugins if you want, if you choosed Community edition
13. If you were owner of Music Collection Professional, you'll need to download this extra file and put in your site, overriding the existing one on folder /components/com_muscol/helpers/version.php. Perform this step only after you installed MC 2 upgrade package.
14. Go to Music Collection backend -> parameters, and take a GOOD look at all the new parameters available. You may want to configure them properly. Spend some time on it.
15. Questions? Be sure you read all the points from 1 to 14 and you performed all necessary tasks
16. Still questions? what about reading point 14 again? ;)
17. Still more questions? Ask on our forum!! Please, try to search before asking anything that has already been asked and answered! ;)