First, you should make sure you are upgraded to the last release of e107 v1, which is v1.0.4. You can find these files here in the "Version 1 (legacy)" area.
e107 0.7.x to 1.0.4 Upgrade, if you're unsure which version of 0.7 you are using.
If you are using 0.6.x, it must be v0.6175 and upgraded using the
e107 v0.6175 to 1.0.4 Upgrade package.
Once you have overwritten your files and ran any necessary database upgrades, you are ready to upgrade to e107 v2.x.
As usual, you should always back up all your files and database before doing an upgrade.