The problem is not that complex.
The wind farm is connected to the electricity grid so... ignore the individual wind turbines, they don't matter. Attack the connecting infrastructure instead.
In order attack (1) the transformers & substations and then (2) the power pylons that connect the wind farm to the electricity grid. One or two aircraft modern fighters could easily handle the mission. (Note: other aircraft would be involved as deemed necessary by the mission planners to cover the attack or bomb replacement parts and roads/bridges as mentioned below depending on the strength of local air defenses.)
Step one would be an attack designed take out the transformers and substations. This can be done using one plane only armed with with standard high explosive bombs (anything in the GBU series deemed appropriate for the size of a specific target) and graphite bombs (US designation BLU-114/B), which are non lethal weapons specifically designed to take out electrical infrastructure.
At the same time a second aircraft could (this mission is more icing on the cake rather than essential) be deployed to take out selected power pylons linking the wind farm to the grid using something like the GBU 24 (Paveway III).
Ideally these would be selected in advance as being the most difficult/time consuming for the enemy to to replace - based on local geography etc. Or just 3 or 4 pylons in a row. Given the nature of the targets (light/strong open framed metallic towers) this mission would probably require larger precision guided munitions but taking out even a small number would significantly delay reconnecting the farm even if the enemy ships in new plant to replace that destroyed by the other attack.
Last points:
If by chance there's a handy fail point (e.g say a bridge across a river, an overpass, a narrow mountain road or some other obstacle on the roads in to/out of the wind farm consider striking that as well in order to complicate any repair attempts.
If intelligence happens to know where any immediately available replacement converters and transformers etc are stored and the risk assessment is low - hit the storage point/s as well.
EDIT; added the designation of suggested weapons systems as requested by author and tweaked the answer to include to include two other possible strike points.)