Without vCenter (in turn vMotion will not be available) , there is one way to move your VM files from 1st host to other datastore and then register on 2nd host but you need at-least shared datastore.
If you can make at-least one shared datastore & your VM files are available on local datastore (not shared), from VI client, login to 1st ESXi host>>power off VM>>Unregister the VM>> goto the datastore where VM files folder available (datastore browser)>> click on VM folders (containing all VM files,ie. vmx, vmdks etc)>> once you click on VM folder, see on the top, you will get move arrow >> Click on move arrow >>It will take you to select the other datastore for moving these files>> select the datatsore which is shared with 2nd ESXi host>>once move operation is complete >> login to 2nd host>>go to the the datastore where you moved your files>> and register the VM by right clicking on vmx file.
There can be other way using vmkfstools but not sure it works even without shared datastore.(I think, it will not work without shared datastore)