Ky1eB513

Just go into the meta, find the handlingid for the slot you want to change, and change handlingid.  See here:
 

<modelName>scpdu5</modelName>       <txdName>scpdu5</txdName>       <handlingId>gresley</handlingId>       <gameName>scpdu5</gameName>

When you replace over a vehicles.meta, or any file for that matter, the new file replaces it entirely.   There are some vehicles that come with a vehicles.meta but they only have a single line in them.  Ideally, if the vehicle has a custom meta line, you are supposed to extract your vehicles.meta and replace over the line that the new one uses.
 
For example:
 
Say you download a new POLICE2, which is a Tahoe.  This Tahoe comes with its own meta line.   You would go into this custom meta, and copy the custom meta for the Tahoe.
 
Next, in OpenIV, go to your vehicles.meta  (mods-->update-->update-->common-->data-->levels-->gta 5).
 
Extract this to your desktop and open it.
 
Now find the line for "POLICE2" and in its place paste the new POLICE2 meta line you copied.
 
You may need to change the new line's modelName, txdName, and gameName to match the slot you want it in.