Hi. As Arman and Neda told 'chetor' and 'chegune' have the same mining. 'Chegune' is used in writing and letters (formal) and 'chetor' is used in informal talking.
Some examples are written below:
چگونه این کار را انجام بدهم؟
چطوری این کار رو انجامش بدم؟ (informal)
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چگونه ممکن است این اتفاق افتاده باشد؟
چطوری ممکنه این اتفاق افتاده باشه؟ (informal)
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چگونه موفق شدی این کار را تموم کنی؟
چطوری موفق شدی این کار رو تموم کنی؟ (informal)
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These two words also can be used in different situation and phrase that it needs to be explain more. For expample "Chetor mage?"
If you would like more feel free and contact with me.
Good luck
Not a chance to use "Chegone" in daily conversations between two people. It used just by formal individuals, Politicians and Broadcasts. Normal people just hear it or read it, and not use it.