How does chromosomal crossing over occur in tightly wound DNA?

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Chromosomal crossover involves segments of chromosomes breaking and reattaching, but this process raises questions about how tightly wound DNA can undergo such changes. The discussion clarifies that, during homologous recombination, chromatin must unwind from its nucleosome-bound state, allowing access to the DNA strands for recombination. This unwinding is essential for the crossover process to occur, as the tightly packaged structure of DNA in chromosomes makes it initially inaccessible for recombination.
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In most of the books I've read, chromosomal cross over has been described as simply "segments of the chromosome breaking off and reattaching", but I have a bit of difficulty with this explanation. Chromosomes are densely packaged DNA that have been wound and wound again. How can DNA which has been so tightly wound and packaged be cut and rejoined so simply? Most of the searches of the recombination process shows recombination occurring between two simple strands of DNA which should not be accessible when DNA is packaged as chromosomes. Does the chromosome uncondense at the part crossing over in order to recombine?
 
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The short answer is yes, the chromatin DNA must unwind from its nucleosome-bound state in order to engage in homologous recombination.
 

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