What does the cryptic crossword clue "All I have to do is to replace dark wool (8)" mean?

The definition is "All I have to do". The wordplay uses an anagram. anagram of DARK WOOL = WORKLOAD The answer is WORKLOAD.

All I have to do is to replace dark wool (8)

Guardian Cryptic #29076 | 24 Across | 2023-05-22 flower