you can bulk update. easiest way is to create new LM and get asset id and replace all the old lm asset id's with new asset id (should be easier than editing all the lms)
SELECT p.RegionUUID, p.UUID AS PrimUUID, p.Name AS PrimName, pi.itemID, pi.name, pi.assetID, pi.assetType, pi.invType FROM primitems pi JOIN prims p ON p.UUID = pi.primID WHERE pi.assetType = 3 AND pi.name LIKE '%OLD NAME%' ORDER BY p.Name, pi.name;
gives you a list / count
like(0)