Complex sentence: Lenin sent a telegram to Józef Unszlicht telling that he does not trust Cheka in Petrograd any longer and ordering to urgently send "the most experienced Chekists to Piter" and find the conspirators.
Split into simpler sentences: Lenin sent a telegram to Józef Unszlicht stating that he did not trust the Cheka in Petrograd any longer. In the telegram, he issued an order to urgently send "the most experienced Chekists to Piter" and find the conspirators.