Just enter "Lam Research Split" in Google and it will appear immediately (e.g. financial news). The copy function somehow doesn't work on my iPhone here in the chat...
@jaheu The split is also included in the new ISIN.
So either enter the new ISIN in the purchases and sales, in which case the split is simply posted to the new ISIN, or enter a sale of the old ISIN and a purchase of the new ISIN.