Simplify the following text for a Grade 10 native English-speaking person.
Original: In the first part of the 1950s , the young Havel entered into a four-year apprenticeship as a chemical laboratory assistant and simultaneously took evening classes ; he completed his secondary education in 1954 .
Simplified: In the early 1950s , the young Havel entered a four-year apprenticeship as a chemical laboratory assistant . He took evening classes at the same time and completed his secondary education in 1954 .