I suggest starting with the following jobs:
* garbage collectors
* butchers
* construction workers
* loggers
* fishermen
* miners
All these fields are heavily male-dominated. All of them are heavy jobs, some of them include challenging work environments. While many jobs need specific training, most of these fields allow beginners to gain experience on the job without having to spend a long time and a lot of money up-front.
If the reaction is "but women don't want to work in those fields" I'd like to know whether this is more important than the strive for 50/50. After all, many men work in fields they're not exactly enthusiastic about. They work there because those were the jobs which where available when (and, sometimes, where) they needed one.
An interesting observation can be made here: the more freedom people - man and women alike - have to choose where to work, the more the sexes differ in their choices [1]:
"Regression analyses explored the power of sex, gender equality, and their interaction to predict men's and women's 106 national trait means for each of the four traits. Only sex predicted means for all four traits, and sex predicted trait means much more strongly than did gender equality or the interaction between sex and gender equality. These results suggest that biological factors may contribute to sex differences in personality and that culture plays a negligible to small role in moderating sex differences in personality.". This study is cited in the first part of the Norwegian 'Hjernevask' documentary series [2], titled 'The Gender Equality Paradox' [3].
[1] https://www.ncbi.nlm.nih.gov/pubmed/18712468
