Shift bytes with Solidity

ShiftBytes.sol

contract ShiftBytes {
    function replaceBytesAtIndex(
        bytes32 original,
        uint256 position,
        bytes1 toInsert
    ) public pure returns (bytes32) {
        bytes1 maskBytes = 0xff;
        bytes32 mask = bytes32(maskBytes) >> ((position * 1) * 8);
        return (~mask & original) | (bytes32(toInsert) >> ((position * 1) * 8));
    }
}