davepreston

maybe it how youve worded the above but
to put bearing into the headstock, you heat the stock to expand it, therefore making it easyer to put in bearings
use the old bearing as a buffer then hit new bearing in with rubber mallet after a good greasing
as for where to get bearings iirc dublin has a bearing manifacturer just ouside the city (google fu) which if you get the size (pm yc) will be a shed load cheaper than buying from ebay or similar